Oscar Fish

This species of fish from the cichlid family known under a variety of common names including oscar, tiger oscar, marble cichlid or velvet cichlid. This can grow up to a length of 45. The Oscarfish, or to give it its scientific name, Astronontus ocellatus. Astronontus actually means being marked with a star on the back. Ocellatus means bearing an "eye spot" The Oscar is a fresh water fish that is a member of the Cichlid (pronounced sick-lid) family which is native to the Orinoco, La Plata, and Amazon river. This Oscar is also found its way into other tropical and subtropical parts of the wild such as some of the canals in Florida USA. However these are not native and were probably introduced accidentally, or released on purpose.



APPROPRIATE HOME

It is not very sensitive and can be kept even by less experienced aquarists, but you must provide it with an aquarium that is large enough. A 100 gallon aquarium is considered a minimum. It will require a pH between 6.5 and 7.0 and water that is soft or just barely hard.In the wild, it is not uncommon for an Oscar fish to grow larger than 30 centimeters When Oscars are kept in aquariums they rarely grow larger than 30 centimeters. In its natural environment the species typically occurs in slow moving white water habitats, and has been observed sheltering under submerged branches. The best tankmates for Oscars are Large Plecostomus and other large Neotropical Cichlids such as Texas Cichlids, Jack Dempseys, Salvini, and other cichlids from South America which are the same size or bigger.

FEEDING

Oscars are large carnivores and they are known to be happy eaters even in captivity.In nature Oscars eat small fish. But in aquariums small fish can introduce diseases. Use live food wisely and try to keep the Oscars healthy by using vegetable based food with vitamins. Crickets, worms, adult brine shrimp and krill are all suitable food types. Frogs and beef heart will also be appreciated. It is easy to train your Oscar fish into accepting prepared food, such as pellets and flakes. A high quality prepared food suitable for large cichlids is recommended. A prepared food can provide a good base, but we should not keep your Oscar fish on flakes or pellets alone. Supplementing prepared food with some of the food types described above is always advisable.

BREEDING

Oscar fish can be bred in aquariums as long as you provide them with favourable conditions. To get a breeding pair, you must house 6 young Oscars together and let them form their own pairs. Make sure you choose healthy Oscars from different broods. It can be hard to sex young Oscars, but you will hopefully get at least one pair from 6 individuals. If you don’t want to wait and let Oscars grow up together, you can instead buy a breeding pair but this is usually much more expensive. The stress and disturbance experienced by the fish when you move them from their old aquarium can also cause them to brake up and stop being a breeding pair. Once a pair has been formed you should remove the other fish from the aquarium, since breeding Oscars are highly territorial and can hurt intruding fish. If the spawning does not commence immediately there is not easy fix that can kick start it. What you can do is provide the pair with suitable conditions and wait for the spawning to start. The courtship behaviour can be very violent – sometimes too violent and resulting in the death of one of the Oscars before any offspring has been produced.Frequent water changes are important to ensure suitable water chemistry and low levels of soluble waste. Do not change more than 25 percent of the water at once. Feed the pair bait fish or frozen fish. Prawns, crickets, earth worms and other meaty foods are also suitable.Pellets should be avoided since a majority of the pellet will slip through the gills of the Oscar and never end up inside the stomach. Raw meat from cows and pigs should also be avoided. An Oscar would dig the substrate or look out for a flat surface for breeding. They are highly protective of there fry's and should be kept alone. Feeding newly hatched brine shrimps are good as the fry grow fastly when compared to that of powerded flake food.

Highlights

This blog contain as many strains/species of Oscar that we can find. Some of them are more of common than others. All the fish on this page have the same thing in common, none of them will be found in the wild. All of these fish have been bred from the original Wild Oscar. Wild, or Common Oscars as they are also known as are still available. However, most of them are bred in captivity and are not taken from the wild. The Red Oscar appeared in the late 60s. It was bred in Thailand. The Tiger Oscar is the closest you will get to the original wild Oscar when it comes to colouring. A true albino is normally white with no colour pigmentation whatsoever. Oscars that have a white body with red or orange are normally referred to as albino. Strictly speaking, they are actually Lutino or Leucistis.

Arowana Fish

Arowana Fish can be a great choice for those that think big. Some varieties can grow up to Four feet long (120cm). They can be feisty, though become tamer with age to the point of eating from your fingers, and not the fingers themselves. The Arowana Fish comes from somewhat primitive origins (Jurassic Age), and some varieties are nicknamed “Bony Tongued Fish”. They are sometimes called as dragon fish. Arowana fish are canivores, though will generally eat nearly anything. Young Arowana Fish may be fed frozen or live brine shrimp, black worms, and even small fish. When older, some larger fish will do. Baby Arowana Fish should be fed maybe 3 times a day, medium sized twice a day, and adults once a day, or even once every other day. Variety is important for a well balanced diet in Arowana Fish just like for most other fish.

APPROPRIATE HOME

Eventually a very large aquarium with an exteriro power filter (The Arowana eating habits produce a lot of waste and you should therefore, pay extra attention to water conditions {Ammonia, Nitrite, and Nitrate} in your aquarium) with a Bio-Wheel, and a maximum of 1/4 inch of gravel. The water temperature should be between 75 and 80 degrees F. Changing 25% to 33% of the water weekly is advisable, or better yet, 20% twice a week. You should maintain the pH neutral. Pay particular attention to the temperature and pH ranges suggested below on the various species, since if you have it too warm, it might cause them to age faster, look less Arowana, and even shorten their life. A to cold temperature might on the other hand kill them.

RECOMMENDED FEEDING

When they are small, Arowanas should be fed live and frozen brine shrimp, black worms, and a few small fish. My friend Fred used to keep his Arowanas in an aquarium with hundreds of small White Clouds. I could see the Arowanas usually did well, but I wondered how many White Clouds were eaten by the small Arowanas. As Arowanas grow larger they are usually fed larger fish. Silver Arowanas have been seen leaping out of the water to eat insects from trees. African Arowanas will survive and grow on the diet given above, but this fish is also a filter-feeder, and feeding filter-feeding fish in aquariums is usually very difficult.

HIGHLIGHTS

Arowana Fish may live for many years, and if well cared for Arowana fish may live longer than 20 years in captivity.

Asian Arowana can be categorised in the following varieties:

Green Arowana - Indonesia
Banjar Red - Banjar Nasin
Red Tail Golden - Sumatra
Golden Crossback - Malaysia
Tong Yang - Hybrid between Golden Crossback and Red Grade 1
Red Grade 1 - Kalimantan (Kapaus River, Sentarum Lake)

Dollar Fish

A longtime favorite for community tanks, there is little doubt where this attractive silvery fish got it name. The Silver Dollar fish comes from South America and has been a favorite among tropical fish hobbyists for many years. Although Metynnis argenteus is the most commonly encountered of the sub-family of Myleinae, keep your eyes open and you'll no doubt see several other varieties at your local pet shops. I enjoy visiting shops in other towns to see which varieties they have on hand. Look for spotted or even striped specimens, as well as ones with fins of different sizes and shapes. These fish are Charcins, and are sometimes mistaken for Pacus or Piranhas. Silver Dollars do grow large and fast so you will probably need a big tank to accommodate them. Because they grow to the size of a dinner plate (8 inches in diameter),

HABITAT

The ideal habitat for Silver Dollars provides them with a large area to swim, as well as places to hide. Subdued lighting and dark gravel is recommended, as well as plenty of plants. When it comes to plants, the Silver Dollar remembers that it's a vegetarian, so consider using the plastic variety. Otherwise be prepared for some casualties among your plant population. Water conditions are not critical, unless you are interested in breeding them.

BREEDING

For breeding Silver Dollars the best tip I can give is to use soft water. Although the parents will not eat the eggs other fish will, so they should not be bred in a community tank. After several unsuccessful attempts I finally had a pair spawn when I set up a tank with very soft water at 80 degrees. The eggs drop to the bottom where they hatch 3 days later.

FEEDING

Silver dollars are vegetarian by nature so they'll eat everything green but seem to avoid things like java moss and java fern as well as toughed leaved plants like anubia.

THE HIGHLIGHTS

They are definitely skittish, and will leap out of the tank if the lid is open and they are startled. Speaking of schools, it is advisable to keep Silver Dollars in small schools of four to five fish whenever possible.

Auratus Fish

The Auratus has a general elongated appearance. The profile of the dorsal area is more curved in than the belly area. The anal and dorsal fins end in a round shape. They do not reach the tail area. The caudal fin is somewhat triangular in shape with a concave end. Females are smaller than males. They are african fish, the southwestern shore of lake Malawi.

THE HABITAT
In the lake, it is not bound to any particular habitat. It occurs both in rocky habitats and intermediate zones (rock and sandy).Auratus is an aggressive fish and intolerant of others in its territory. The set up should be a typical Lake Malawi biotope. Plenty of rockwork and caves with hard alkaline water with a pH of at least 7.5 is needed. The bottom substrate should be of a material that will aid in the pH buffering capabilities of the water. Good substrate choices could be Dolomite or crushed coral to aid in buffering the water. Tankmates should be from the same area and be able to fend off their attentions. Feeding is not difficult as they will accept all types of flake frozen or live. In their home territory they would graze of the algae covered rocks called Aufwuchs, so it is important to supplement with food containing spirulina and this should be given regularly.

BREEDING
Not really difficult, they are a typical African mouth-brooder incubating the eggs and protecting their fry in special sacs in the mouth. They are excellent and protective parents and have been known to raise young in crowded community set ups. During this brooding the female will not eat. The young fish will leave the mothers mouth after about twenty five days and be about 1/3 of an inch in length. They will accept all types of food and can grow quickly.

FEEDING
Melanochromis chipokae is easy to feed. In the lake it is a true omnivore. Reports have found filmentous algae, zooplankton and cichlid fry in the stomachs of wild caught individuals. Provide a good quality cichlid flake and spirulina flake.

COLORATION
The Auratus have two distinct coloration patterns differentiating the sexes. The females body is a golden yellow. She has a series of three Black to brown stripes running lengthwise down the body. These are fringed by White strips. The bands are separated with the Golden color of the body. The fins are also yellow in color. The upper part of the tail fin and the dorsal fin have black markings on them, with the tips being highlighted in Red. The male is completely different in color. His body is Black to brown in color. He has a Yellow stripe edged in white running the length of his body. The males fins are very dark Brown fringed in White. The top of his body is a mustard color which is followed up through the dorsal fin. The upper part of his tail fin has pale yellow spot. Looking at these fish you would not think that they are the same species. Another interesting aspect of the auratus is its ability to change sexes, in an environment devoid of males a female will switch sexes and become male. It has also been stated that the same is true of the males.

THE HIGHLIGHT
The species grows to 12 cm (even more in an aquarium) and is regarded among the most aggressive mbunas. It should be housed with species of equal or bigger size and of the same temperament. Keeping more than one male in a tank is almost impossible in tanks smaller than 150 cm (450 liters). Even then, all other males will be probably killed by the dominant one. Despite the presence of two females, my dominant female killed the submissive one in less than a month. Females are also territorial and intolerant of their own species and are extremely aggressive when carrying eggs. It is not unusual for a male M. auratus to kill one or more of the females. This is especially true in small tanks so I recommend you take the minimum tank size seriously into account if you plan to keep this fish. A Juvenal looks alot like the female and I think the biggest difference is that a female will have black/dark blue along the top portion of her tail. Also Juvenals color patterns don't seem to be as well defined. The common name for them is Golden Cichlid.

Jewel Fish

The Jewelfish, also known as Jewel Cichlid or JewlFish, is from the family cichliade, and can grow up to 6 inches long. The origin for the African Jewelfish is in the Nile river, Niger , Congo river. It's originally from Africa and is the most beautiful, bellicose, aggressive and eager to fight, of the cichlids. There are lot of different species of the Jewelfish. All different species behave the same and have the same conditions. The Jewelfish is not a community fish (they are ferocious) and cannot have any other fish in a tank with them. Due to them being so beautiful many people like to have them as pets. They grow upto to 5 inch and live for a maximim of 8 years.



Environment
The are found in very high numbers in the rivers of west Africa, but have also spread to areas of the middle east, and also to parts of South America. Just recently, they where discovered in areas of North America around the Gulf Coast, in states such as Florida. Also they can be found in creeks, streams, lakes, and rivers. Since they are from Africa, it needs soft and a bit more acidic water in order to stay alive in captivity. They live in water that is partly salt water and partly fresh water and is in a tropical location because it prefers a water temperature of 75 to 85 degrees. When in captivity, the African Jewelfish must be kept alone, as it is a very aggressive fish and will feed on another fish of its kind. Need to provide lot of hiding place for them to safety.



Breeding
They will turn a deep red color to let the male know (When the African Jewelfish is ready to breed). The male and female will bond or jawlock and the male will release sperm on the eggs. The female will then lay the eggs on a flat surface - usually a dugout in the back of the aquarium, although you can provide flat rocks to encourage them. The female will protect her eggs and will kill anything that comes in close proximity. In a couple of days the eggs will hatch and the female will still protect them. The female can reproduce every three weeks.



Food
The Jewelfish are carnivorous. They feed on insects and Caridina. Caridina are associated with shrimps and prawns. They can also eat some plants, such as algae and other weeds, as well as debris. During captivity, African Jewelfish can live by you feeding them varied diet of frozen, live, flakes and pellets as they usually accept mostly all forms of fish food. The also eat algae wafers and shrimp pellets. They can be easily compared to the bottom feeding fish in an aquarium, as they like to eat the algae and other depris that forms in the tank. Jewelfish are also known to eat their own young because they are carnivorous.



Color Strains
Turquoise jewels definitely sport a different color. Is it turquoise? Perhaps. They seem to blotch out the jewel’s regular sparklies and make them less red (or blue) and more of what some call turquoise. The colors in the turquoise below exist in the regular jewels. When the two strains cross, we’ll see more variations. Not in the betta, platy, or guppy rainbows but definitely more colors. They are also found in green and red color, which are very common.



Highlight
“Jewel” refers to the little iridescent sparklies (the maculatus or “spot” in their scientific name) that cover their bodies -- not their colors, and certainly not their personalities.

Flowerhorn Fish

This fish is very hardy, and can endure water conditions that are not suitable for some types of aquarium fish. Their hardiness is one of the big reasons that the Flower Horn is enjoyed by many tropical fish hobbyists. The ideal water temperature ranging between 75 and 80 degrees F. Flower Horns will quickly grow to be over 12 inches long, and some have grown to be over 16" long. They may live to be 8 to 10 years old.


Parents
These beautiful hybrid fish are result of cross breeding various Cichlasoma species such as C. trimaculatus, C. festae, the Jingang Blood Parrot, and perhaps other species too. The best quality Flower Horn Fish have been produced by fish breeders that are eager to produce the best show quality fish. The Flower Horn Fish has gone through several generations of selective cross breeding to capture the best characteristics of various different species.
Most breeders are striving to produce Flower Horn Fish with bigger nuchal hump on the forehead, better coloration, bolder black marking on the body (which at times resembles Chinese characters), more elegant fins, and wider body. But neither chemicals or genetic engineering have been used so far to improve on the traits or characteristics of the Flower Horn.

Basic Traits
As flower horn fish is from the South American Cichlid family (under the genus Cichlasoma), this fish is very aggressive and territorial in nature. Coexisting with other fish is not advisable. Thus, if you plan to have 2 or more fish in a tank, it is a requirement that you have the tank partitioned. This will prevent the fish from fighting that may lead to even death.

Tank Environment
In general, it is important that we provide some furnishings for the fish. The intent is to stabilize and make it feel more at home. All that is required by flower horn fish is to have a thin layer of gravel in the tank. Bare in mind that stressed fish will cause the fish to loose its coloration, nuchal hump and may stun its growth.

Feeding
Flower horn fish has very good appetite. This hybrid can either take live food or fish pellets. It is advisable to feed the fish several times a day in small quantity. Ideally to have a mixture of life and fish feed. This will make the fish healthier. Besides, the intensity of coloration greatly depends on the diet of the fish. Excessive feeding of color enhancer is not advisable as it may contain harmful chemicals. Please do it in moderation.

Bredding
Breeding Flowerhorn cichlids are easy but it can be hard to get the offspring you want as this requires selective line breeding. You have to carefully choose the parents you want to breed from if you are looking to get a specific type of Flowerhorn fish as the outcome of the planned spawning.To breed your Flowerhorn cichlids after choosing the parents you want to use you can proceed in the same way you would with many other large South and Central American cichlids. Which is quite natural since Flowerhorn fish is a result of selective cross breeding of different South and Central American cichlids.This text will teach you the basics surrounding Flowerhorn breeding and is assuming that you have basic aquarium and breeding knowledge. It is best to keep your Flowerhorn cichlids in a large aquarium to breed them and to decorate the aquarium so that there are hiding places for the female and so the male doesn't always have a clearline of site to everything happening in the aquarium. Flowerhorn cichlids can be very aggressive towards their partner and a well decorated aquarium is not always enough to protect your female from the male's advances and aggression. Keep and close eye on the couple and if you se that the male is to aggressive you should remove the female from the aquarium . You will in that case have to attempt Flowerhorn breeding using a separator so that the male can't get to the female and hurt her. Leave a small gap between the bottom of the aquarium and the divider. The gap should be too small for any of the fish to fit through. The only decorations in the breeding aquarium should be a flat stone placed with the female next to the divider. This is done to force the female to deposit her eggs on the stone where the male still can fertilize them thanks to the gap between the bottom and the divider. The filtration in the aquarium should when attempting Flowerhorn breeding be arranged in such a way that the water flows from the males side to the females side as this facilitates fertilization.Flowerhorn breeding can be achieve in most water conditions but a neutral pH level and a temperature around 28°C / 82°F is optimal.you will have to condition your Flowerhorn cichlids prior to breeding. This is relatively easy achieved since Flowerhorn cichlids accept most kinds of food and a diet consisting of pellets and some shrimps and other food for variation will do well.

HUMP
The hump near the head of the flowerhorn is full of fat. Using the pellets that will enhanse the hump of flowerhorn for appearance. Blackworms, Goldfish will also speed up the growth of the hump. In order to produce the hump in flowerhorn, keep a mirror
outside the tank, as it sees the mirror, the flower horn wil become aggressive and will start hitting the glass with its head. This will result in the increase of the hump ( this information was given to me and i am not sure about this ).To make it grow faster ,there are special pellets called "HUMP HEAD" availabel in the market.

FLOWERHORN FACTS

• THIS FISH IS NOT A NATURAL ONE,IT IS A CROSSBREED OF CICHILDS

• THIS BEAUTIFUL FISH CONSIDERED AS "FENGSHUI" BY THE CHINESE MAY FETCH HUNDREDS OF THOUSANDS OF DOLLARS.

• THESE FISH HAVE AN EXCESSIVE APPETITE

• IT EATS BOTH VEG AND NON-VEG FOOD

• VEG INCLUDES PELLETS,PLANTS ETC.

• NON-VEG INCLUDES FISH,PRAWNS,GRASS HOPPERS ETC.

Parrot Fish

Parrot fish are normally tropical fish and they prefer warm water bodies. They origin is supposed to be Taiwan or Singapore. They prefer to have temperature around 75 to 80 and prefer to have clean water.

Parents
Its parentage is unknown, but the most commonly speculated pairings are midas cichlid (Amphilophus citrinellus) with the redhead cichlid (Cichlasoma synspilum), or the severum (Heros severus) with the red devil cichlid (Amphilophus labiatus).Blood parrots should not be confused with other parrot cichlids or salt water Parrotfish (family: Scaridae). Because the blood parrot is a man-made hybrid it doesn't have a scientific name nor will it be given one.
Unique character Parrot fish are known for its peculiar shape mouth, which normally is always open and the head of the fish looks like that of a parrot. They use the muscles in the throat to chew the food. They have hard time in catching fast moving live prey and also have to make few attempts to catch man feed food itself. Parrot fish also have a deformed spine, this is the reason behind their unique shaped body.

Parrot cichlids can grow to 8 inches in length or more and can reasonably live for several years.


Activities
Parrot fish are normally shy kind of fish and prefer to hide themselves on introducing to new environment. They tend to shed their shyness during few weeks of their exposure of the new environment. Some time it may take months for them to lose their shyness. Normally as aquarist, to move the parrot fish out from the shyness we used to have “Dither fish” in the tank. Few names of dither fishes are Dollar fish, small varieties of tetra’s.
These fish also tend to dig a lot of the substrate provided to them. They are normally docile, but it may vary with fish to fish. They also used to have lip fight when they are trying to defend their territory. But at nights they used to share the same place for taking rest.

Parrot fish are good sturdy kind of fish. They change color to black at times when they are mating.


Different Types
The very common types of parrot fish found are Red Blood parrot fish are not normally red, but they are usually of different shades of gold orange colors. There is also a Purple blood Parrot fish available, which are bright red color.
We also have a new strain of fish called “Love Heart Fish” which do not have tail. Even though they tend to move as easily as other parrot fish does. We do also have “Lipstick Parrot Fish” available in lot of LFS(Local Fish Shop) which have lipstick kind of makeup given to the

Parrot fish come in many other colors through dye process, which is supposed to be a very cruel process. The next best part in this cruelty is, that the color does not stays and it fades away. The mortality rate during this process is very high, which is very bad.As mentioned, they come in a variety of colors. Recently many people have been noticing their blood parrots changing colors as they get older. This isn't at all surprising when you consider the parent species. Both midas cichlids and red devils can change colors substantially in the wild to a large degree. Try not to purchase any dyed parrot fish and let’s make sure that this kind of cruelty is not done in mere future.

Fresh Water Aquarium

FRESH WATER

This type of water is also known as Continental water, a more accurate term from the scientific point of view. Continental water accounts for only 2.6% of the Earth's water, the rest being made up of seas and oceans. Of this volume, 98% consists of sterile water, in the form of glaciers and underground water, leaving only the water of rivers, lakes, and ponds as shelter for living organisms- barely 2% of the total volume of Continental water.


WATER CHANGE
For some hobbyist, water change is a chore that they dreaded most. In order to have a well maintained tank, periodic partial water change should be done at least once a month. Be aware that clear water with stable water pH and excellence water temperature does not indicate that the water in the tank is clean. Besides, there is no filtration system that is able to keep the tank 100% clean. Furthermore, regular water change will ensure the growth and health of the fish. Be doubly aware that regular topping up of the water in the tank does not count as water evaporates. The waste from the fish still stays behind.


WATER MOVEMENT / FLOW
Most of the time, the flow of the water in the tank is overlooked by hobbyist. But it is vital to the health of the fish.
Below are some of the important factors:
• Alleviate the possibility of thermal layering. In other words, uneven distribution of water temperature.
• It also helps to distribute oxygenated water in the tank.
• It prevents the formation of thin film on the water surface that will hinder the gaseous exchange between air and water in the tank.


TEMPERATURE
An important parameter for aquatic life, the temperature regulates the growth of animals and plants and exerts an influence not only on oxygen levels but also on many other factors. Whereas mammals have a regulated and practically stable internal temperature, that of fish and other aquarium creatures varies according to the temperature of the water around them. They can survive only at certain temperatures and some species are more sensitive than others to variations in this parameter. The temperatures of fresh tropical waters, ranging from 20 to 30°C, are characterized by less significant variations than those found in temperate regions. In some places the shade provided by the tropical forest cools the water, while in calm water the temperature goes up under the direct influence of the sunlight. The mean temperature most often recommended for aquariums is 25°C, and variations of 1 or 2° are of little consequence. Fish are even capable of withstanding even more significant variations for brief periods (under 24 hours). On the other hand, their metabolism (i.e. their general bodily functioning) is in danger of serious disturbance over any longer periods, and sooner or later they may die. It must also be noted that excessively low temperatures sometimes favor the development of certain diseases.


OXYGEN AND CARBON-DIOXIDE
Since air contains around 20% oxygen, even the most oxygenated water rarely contains more than 1% dissolved oxygen. Fish have special organs - branchiae -which allow them to extract most of this Oxygen contributes, in addition, to the respiration not only of plants but also of organisms which are invisible to the naked eye and often forgotten: the bacteria. The latter transform the organic matter emitted from living beings (excreta and various other residues), and these chemical reactions similarly requireoxygen.The oxygen in water comes from the dissolution of the oxygen in the air, a process enhanced by movements in the water produced by wind, currents, or downward flow. The more water is stirred, the more it is oxygenated. Plants also provide oxygen, which they produce through photosynthesis, although this process occurs only by day. The maximum amount of oxygen that water can contain is determined by its temperature: the higher this is, the less oxygen the water can contain (at 25°C there is 18% less oxygen than at15°C).Oxygen is measured in mg/liter, and its control is quite a complicated matter. The most turbulent, and therefore the most oxygenated, water contains 8-10 mg/liter, while the most deficient water sometimes has less than 2 mg/liter. The oxygen content in an aquarium is usually at its maximum, providing the recommendations for stirring the water are followed. The rare problems which do occur are the result of negligence as regards the overall balance of the aquarium (overpopulation of fish, small number of plants), or non-functioning of equipment due to forgetfulness, breakdown, ora power cut. Carbon dioxide derives from the respiration of fish, plants, and bacteria. Stirring the water enhances its oxygenation, thereby reducing the levels of carbon dioxide in the water, and passing it into the atmosphere. Carbon dioxide is quite rare in an aquarium, and this can, to some extent, prove prejudicial to plants, as they absorb it by day through photosynthesis to extract the carbon they need to grow. It is therefore vital to establish a permanent equilibrium between oxygen, carbon dioxide, plants, and fish, although this balance changes at night, when plants stop producing oxygen. Carbon dioxide is also one of the main factors affecting the pH.


SALT AND ITS BENEFITS
Salt at times acts like a stabilizer. But in some areas, the dissolved salt content in the water is low, and the addition of aquarium salt might simply make the fish feel more “at home”. It acts like a disinfectant as it helps in killing certain parasites. Salt also provides sodium and chloride ions that helps fish stabilize.


PH VALUES
The pH measures the acidity or alkalinity of water, with the value 7 representing neutrality. Below this level the water is acid, and above it the water is alkaline (or basic). Categorizing water as acid does not mean that it contains dangerous acids. In forest streams and rivers the water accumulates with acid organic fluid (humic acid) derived from the decomposition of plants (humus), producing an amber yellow color. Generally speaking, aquatic life can exist only between pH 5 and 9. These extreme values are rarely found in an aquarium, where the pH ranges from 6 to 8 according to the type of water, and usually lies between 6.5 and 7.5. In aquariums, the term acid water corresponds to a pHbetween 6 and 6.8, while alkaline water refers to one between 7.2 and 8, and a pHbetween 6.8 and 7.2 is considered neutral. Variations in pH are mainly the result of biological activity: the carbon dioxide produced by living beings acidifies the water at night and the pH goes down slightly. Once the carbon dioxide has been absorbed by the plants during the day thepH goes up again. Although slight variations are therefore normal, more extreme changes can be a warning signal. The pH is a good indicator of an aquarium's equilibrium, and it should therefore be measured regularly. A colored marker dipped into a sample of water is used to compare the color obtained with the scale provided. Electronic meters are also now available for testing pH values.


ADJUSTING pH
The pH of domestic water may not always be particularly suited to the fish you have chosen. Furthermore, when an aquarium is in use the pH can rise and fall, slowly but very regularly. There are some aquarium products on the market that enable adjustments to be made to the pH, but there are other ways of modifying it.• If the pH is too high- the water can be diluted with another more acid water;- the stirring of the water can be reduced. Carbon dioxide is eliminated less quickly and remains in the water to acidify it. Be careful, because decreasing the stirring also lowers the oxygenation; - the water from the aquarium can be filtered over peat, which will release certain acids. The amount of peat needed to maintain a specific pH value must be found through trial and error, with regular measurements of the pH.• If the pH is too low- the water can be diluted with another more alkaline, and generally harder water(see Hardness, below);- the agitation of the water can be increased, enhancing the elimination of the carbon dioxide dissolved in the water and therefore lifting the pH;- the water can be filtered over calcareous material, rock, or oyster shells broken into little pieces. In this case, the hardness also increases (see below).


HARDNESS
The hardness of water refers to the combination of substances based on calcium (Ca) and magnesium (Mg) that are contained in it. The main substances, known as salts, are carbonates, bicarbonates andsulfates.Water with zero hardness does not contain any of these salts; this is the case with distilledwater.The water in some areas can be particularly hard, mainly due to the presence of limestone (or calcium carbonate).The hardness of water really depends on the land through which it has passed: the more calcium and magnesium the rocks contain, the harder the water. The effects of this can be seen in domestic use: a washing machine, for example, will require more detergent. Above certain limits of hardness water is unfit for human consumption or any other use. Water with a low degree of hardness, i.e. containing few calcium and magnesium salts, is considered soft. Water with a high degree of hardness is classified as hard.


WATER, A HAVEN FOR LIFE

PEAT
Peat derives from the decomposition of vegetation in an acid environment lacking in oxygen. This process, which lasts several centuries, gives rise to a peat bog from which compact, fibrous peat can be extracted. It endows water with both a yellow amber color and acidity, which gives it slightly antiseptic properties. This means that some diseases are less common in acid water. The use of horticultural peat, which often has been enriched with various products, must be avoided in favor of the peat for aquarium use that is commercially available. Boil it for around 15 minutes before use. In the Amazon region of South America, the color of the water ranges from amber yellow to brown, due to the leaves and branches floating in it. In an aquarium, peat can be used in the filtering equipment to reproduce the characteristics of this type of water (low hardness, pH under 7, coloring). The hardness of water is expressed in German degrees (°GH or °DH), not to be confused with Celsius degrees (°C) for temperature: 1°GH is equivalent to 17.9mg Ca/liter, or 17.9 parts per million (ppm). The term most often used to classify hardness is general hardness (GH), although total hardness (TH) can also beused.There are three main categories of water in fish keeping:- soft water, which is generally acid, at3°GH or 50 ppm;- medium water, which is neutral or slightly alkaline, at 6°GH or 100 ppm;- hard water, which is highly alkaline, at12°GH or 200 ppm.We will go on to discover that some fish families can adapt only to certain types of water.


MEASURING GH
A colored indicator is used: the number of drops needed to obtain a change in color indicates the degree of hardness. It should be noted that the degrees of hardness used in analysis kits may vary according to the country in which it was manufactured; in some cases French degrees are used. These can be converted as follows:1°Fr=0.56°GH• How can the degree used by a manufacturer in a product be identified? To confuse matters further, you may also come across °Clark in older books on fishkeeping.The old-fashioned Clark system for hardness was somewhat laborious, being based on measurement of the foam created by a soap solution, and has now become obsolete. If you have any doubts about the units used by the manufacturer of an analysis kit, just measure a GH you already know, such as that of bottled water.


THE RELATIONSHIP BETWEEN GH and CH
We have already seen that significant changes in the pH are prejudicial to aquatic life, especially if they occur too abruptly. To compensate for this, nature has provided a screening device, the CH (carbonate hardness,i.e. the hardness due to calcium and magnesium carbonates and bicarbonates).The higher this is, the less the risk of any major variations in the pH. and vice versa. This phenomenon, known as buffering, can therefore only occur in acid fresh water. There is a relationship between the CH and the general hardness: the closer the CHvalue comes to the GH value, the more balanced the water. If the CH is less than 75%of the GH, you are likely to encounter a problem, and it is therefore not advisable to use water with these characteristics in anaquarium.Modifying the hardness of water Sometimes the water available presents a hardness value inappropriate for its intended use in an aquarium. In most cases, the water will be a little too hard, and so the GH must be brought down for use in a mixed aquarium or a rearing tank. In other, less common cases, the water can be slightly too soft, and so the GH needs to be raised. Reducing the GHWater with a low hardness value can be mixed with water that is too hard. There are several alternative sources of water
- Rain water
- Spring and well water
- defrosting water from a refrigerator
- Water from melted snow
- distilled water, available in bottles
- Some brands of mineral water
- Natural flowing fresh water
The volumes of water that can be obtained, and its price, obviously depend on which of these sources is used. Filling a tank with a capacity of several hundred liters with water of a precise hardness can sometimes be a laborious process. A final piece of advice: avoid using water from a domestic softener, as the calcium salts are replaced by other salts. Osmosed water(see page 17) is an attractive option, but the equipment represents a substantial investment.• Increasing the GHThe water in question can be diluted with harder natural water, generally easier to find than soft water, or put some calcareous rocks in the aquarium, regularly monitoring the GH, or filter the water over oyster shells crushed into tiny pieces. Any modification in the hardness of water is matched by a modification in the pH: increasing the hardness of the water also increases its pH, and vice versa.

TURBIDITY

The turbidity of water refers to the presence of suspended matter - either living organisms forming plankton (rare in an aquarium) or inert matter, such as animal or vegetable remains or particles of sediment, particularly mud. The size of this suspended matter ranges from a few thousandths of a millimeter to several millimeters. In calm, unstirred water it forms sediment at a speed in proportion to its weight. In running or turbulent water, some of the matter remains permanently suspended, giving rise to more pronounced turbidity. In aquariums, where the water is always in motion, systems of varying degrees of sophistication (see Filtration, page 237) allow fish keepers keep their water clear. The effects of this are entirely positive- The visual appearance is improved- The light required by the plants penetrates the water and reaches them more easily- There is less risk of disease, particularly in the fishes' branchiae- There is little sedimentation on the base of the tank, reducing both the possibility of any warping due to excessive weight and the decomposition of organic matter.

NITROGENOUS PRODUCTS AND THE NITROGEN CYCLE

Nitrogen (N) is one of the components of certain substances, largely derived from the excretion of fish, that are dissolved in water. These substances, of varying structural complexity, are quickly converted into ammonia (NH3 or NH4+), which is highly toxic for animals. At this point oxygen and bacteria intervene to convert the ammonia into nitrites (NO2-), which are also very toxic. Other bacteria, still accompanied by oxygen, transform them in their turn into nitrates (NO3-), slightly toxic for fish but which can be used by plants as nutrients. These transformations, taken as a whole, are referred to as the nitrogen cycle. In nature, land-based elements can also participate (see diagram). As plants are at the base of the food chain, they also take part in the nitrogen cycle. In an aquarium, the situation is different. Some fish partly feed on plants, but most of them are fed by the aquarist; sometimes there is a surplus of foodstuffs and the nitrogen cycle is altered as a result. It is very important to respect the equilibrium of this cycle. That is why you should not keep too many fish and you should not overfeed them. It is also a good idea to provide the aquarium with a sufficient amount of vegetation, and to enhance the development of bacteria, while ensuring that the water is well aerated. Partial and regular water changes make it possible to eliminate surplus foodstuffs, various types of organic matter, and any nitrates that have not been used by the plants. A biological filter enhances the development of the nitrogen cycle.

Bacteria in the nitrogen cycle

Rarely found in open water (around 1% of the total count), bacteria colonize essentially the floor and the decor. They feed on nitrogenous compounds in the water, extracting the oxygen from them. When an aquarium is brought into use, bacterial colonization of the environment is a slow process, and so it is advisable not to introduce the selected fish until 2 or 3 weeks have elapsed.

The toxicity of nitrogenous compounds

The concentration of nitrogenous compounds in an aquarium is higher than in a balanced natural setting, and there are some limits which must not be exceeded(see table above).Ammonia is found in two different forms in water, and the sum of the two must not be more than 0.4 mg/liter. Dissolved NH3ammonia gas is the most dangerous, although it only appears above a pH of 7and rarely exceeds 10% of the total ammonia. The more common ionized NH4+ form is slightly less dangerous.

LEVEL OF NITRITES (NO2-)

No nitrogenous substance should pass the threshold limit in a well-balanced aquarium. As ammonia and nitrates are more difficult to assess, it is the nitrites that must be analyzed regularly. There is a colored marker commercially available, which gives a stronger color according to the amount of nitrites present. If the latter are too abundant:- either there is a general imbalance (too many fish, too much food in the water) which entails a high production of ammonia and, therefore, nitrites;- or there is a problem connected with the transformation of nitrites into nitrates, often a lack of the oxygen required by bacteria. The level of nitrites, like the pH level discussed above, is a good indicator of the equilibrium of an aquarium, and it is therefore important to measure it regularly.

OTHER DISSOLVED SOLIDS

A great many other substances are to be found dissolved in water. Their content is generally low and does not pose any problems, and some of them, such as micronutrients, are even very beneficial. This term covers a variety of elements including vitamins and metals, which in tiny quantities are indispensable to life. Iron, for example, plays a role in the composition of hemoglobin, the red blood cells which transport the oxygen taken in by the branchiae. It also participates in the photosynthesis of plants, which have a tendency to turn yellow if there is an iron deficiency. Manganese is equally important, as it is one of the components of chlorophyll, the green pigment in plants that allows them to absorb light and develop. There are, of course, other metals that are also naturally present in water, but their concentration hardly ever exceeds a few thousandths of a mg/liter, and some, such as copper, become toxic if it goes beyond this limit.

Origin and quality of fresh water used inaquariums

The simplest and cheapest means of obtaining water is turning on a faucet, but there are other possibilities, especially when it comes to obtaining natural water.

• Domestic water, as long as water is drinkable, there is no reason why it is not suitable for fish. In some regions the water is sometimes too hard (general hardness above 11°GH), and so the option of mixing it with softer water must be considered. Domestic water must never be introduced in large quantities into an aquarium which already contains fish. It is also advisable to let it settle for 24 hours to eliminate any excess of gas (caused by the pressure).When filling a tank before putting it into operation, this step is not compulsory, as it will not be housing fish immediately.

• Natural water close to home usually shares many of the characteristics of domestic water, as it makes up a large part of the public water supply. However, it should be possible to find water with different characteristics not too far away.

• Spring water is the most desirable water, as it is the purest, with no suspended material, little or no organic matter and a high bacteriological quality.• Well water is of a similarly good quality, although it sometimes contains an excess of gas. It can occasionally be slightly ferruginous (containing iron), which favors the growth of plants.

• Rainwater is soft and acid, so is useful for diluting water that is too hard. It should be collected in plastic containers; if these are put under a gutter, take care not to collect the first water, as this will have cleaned the roof. In urban and industrial areas, rainwater is liable to contain pollutants, and it is therefore not advisable to use it.

• Stagnant water (ponds)and still water (downriver)Such water can pose a microbiological risk, and it is not advisable to use it.

• Demineralized and distilled water Their pH is neutral or very slightly acid, with little or no hardness. Their high price means that they are only used for mixing with hard water, or for filling a small rearing aquarium. Do not forget that softened water cannot be used.

• Bottled water This is often referred to as mineral water -erroneously so, as some brands contain hardly any minerals and are quite soft. These are certainly not used to fill up huge tanks, bottle by bottle, as this would be too expensive and time-consuming, and therefore serve a similar function to that of distilled water.