Kalkwasser is German for 'Lime water'.  Kalkwasser is used as a calcium supplement in marine aquariums. Marine organisms draw calcium from the water to form their skeletons and shells.  Hence, the calcium level in the water gets depleted.  This has to be replenished.

Kalkwasser is a solution of calcium hydroxide in water at a high pH usually above 12.

Hence, care should be taken in handling and preparing it.

Kalkwasser should be properly dosed.

Kalkwasser reacts with carbondioxide in the atmosphere and becomes calcium carbonate which is insoluble. Hence, it cannot be stored for long and should prepared before it is added.

Carbon Dioxide Tablets are tablets which are added into the water.  These Tablets claim release to carbondioxide slowly in the water.  They are used in planted aquariums where the plants need carbondioxide to grow.

However, skeptical aquarists say that these tablets release the carbondioxide too fast to be of any use. They may have a marginal effect in small aquarium.  Big Planted aquariums need other methods of Carbondioxide addition.

If you are going to try the tablets.  Keep the following things in mind.

However, the dosage should be carefully followed.  The dosage is generally mentioned in the cover. Eg. 1 tablet or 2 tablet per 50 litres.

The level or carbon dioxide affects the pH of the water.  Any drastic change in the pH can be fatal to the fish.

At night plants give out large quantities or carbon dioxide.  This can affect the fish.  Hence, it is better to start at small doses and then go the recommended dose.

If you find fish gasping for air in the surface in the morning, stop using the tablets.

Fish supplements are substances added to the fish tank in addition to the normal food to ensure proper development and health.  Supplements are usually used in reef aquarium containing corals and other shelled invertebrates.

Calcium is a very common supplement as it helps build the shells or snails, crabs, shrimps, etc.

Iodine, iron, magnesium are all important elements which are provided as supplements.

Garlic is an example of a common aquarium supplement.  Garlic helps the immune system of fish fight disease.  Food can be soaked in these supplements or the supplements can be added directly to the water.

Many ready made foods come with the necessary supplements already added.

Aquarium fish water is rich in plant nutrients and nitrogen based compounds.  They would make ideal fertilizer for household gardens.  If you are an aquarium keeper, you can keep a small garden ( at least a few potted plants if you live in an apartment).  This will help you utilize the waste water from your aquarium.

However, do not use the water if you have added medication or any pesticide for algae or for snails.

These pesticides can affect the plants.  Hence, use the water only if you have not added any medication or chemical to your tank after the last water change.

Foul Smell in a fish tank is an indication of poor maintenance.  The smell in the fish tank is caused due to ammonia.  This indicates that the biological filter is not working or that the fish tank is overloaded (Excess bioload).

Periodic partial water changes ensure that the ammonia and other wastes are removed.  If water changes are not done in time, your tank will smell bad.

Fish Tank smell can also indicate death of fish.  Sometimes, fish can die in places which are not easy to see, behind filters or plants.  Decomposing fish cause a spike in the ammonia level causing the smell.

Overload of the aquarium with more fish than it can handle is also a reason for the tank to smell.

Sometimes, the nitrifying bacteria which provide biological filtration can be killed by medication used to treat disease.  This causes the ammonia levels to spike causing the smell.

Bioload is the total waste generated by the tank.  It includes the waste produced by the fish, the uneaten food, the decomposing plants and dead fish.  In a healthy tank, the bioload is removed by the nitrifying bacteria and by frequent water changes.

Dead fish and decomposing plants should be removed immediately.

If the tank is not cleaned regularly or if the filtration is not proper, the bioload accumulates in the tank.  Soon, algae spread over the tank due to the food available.  Brown bacteria also begin to cover the tank surfaces.

These bacteria and algae require oxygen to survive.  They absorb the oxygen in the water which deprives the fish of oxygen.

One of the first symptoms of excess bioload is the fish coming up to the surface to breathe.

Bioload which is not removed will result in increase in ammonia and nitrates which will eventually kill the fish.  A foul smell emanating from the tank is also indicative of excess bioload.

Gold Fish do not have stomachs as is technically defined.  However, different parts of the intestines of a Goldfish do the function of the stomach.

The stomach in other animals serves to store food for a while before being sent to the intestines for absorption of the nutrients.  Since, goldfish do not have stomachs, they cannot store food.  Hence, the food they eat passed through the intestines and is immediately excreted.

Hence, Goldfish should be fed in small amounts 2 or 3 times a day.

Overfeeding is a mistake many hobbyist make, at least, in the initial stages.  Overfeeding means that the fish do not eat all the food.  The uneaten food decomposes and contaminates the water.  Overfeeding also causes digestive problems to the fish and dirties the water in the aquarium.

A general rule of thumb is to ensure that the food you drop into the tank is consumed within 5 minutes.  If the food remains uneaten for more than five minutes reduce the amount during the next feed and you will soon know the optimum amount to be fed.

The amount of food will vary with the time of day and with the number of fish.

Live Rock is used to provide a background in marine aquariums.

Live Rock refers to the skeletons of long dead corals.  These skeletons are composed of calcium carbonate.  Contrary to what many people imagine, Live Rock is not actually "live".  What makes it live are the many microscopic algae, bacteria and tiny invertebrates that live in it.

The bacteria serve as biological filters and breakdown the ammonia and the nitrites.  Live Rock help in making the aquarium resemble a natural sea environment.

Live Rock is obtained from coral reefs from the seas.  There are different types of Live Rock depending on the place they come from such as Fiji Live Rock, Tonga Live Rock and so on.

Live Rock should be obtained ethically.  In many parts of the world, unscrupulous dealers break live coral and sell it to hobbyists.  This is illegal in many places.

Most Genuine products are collected passively which means that the rocks break off naturally due to tidal and wave action and wash ashore.

Plants require carbondioxide to prepare food through photosynthesis.  Hence, maintaining adequate levels of carbondioxide is essential in an aquarium with plants.

Carbondioxide occurs naturally in the aquarium from fish respiration and other microscopic processes.  This is sufficient for plant growth.  However, some hobbyists interested in faster and richer plant growth add carbondioxide to the water.

Carbondioxide can be added by a simple home-made yeast fermentation bottle.  The outlet of this bottle can be fed to the inlet of a power head.

There are ready-made carbondioxide reactors available in the market.

Some pet stores offer carbondioxide tablets which is to be dropped into the water.   These tablets release water over a short period of time.   The effects of  these tablets is debated.

Male Guppies are bright in color and have markings all over their bodies.  Female guppies have markings only on the tail.  The body is dull colored, often semi-transparent.

In addition, male guppies have a gonapodium, a modification of the anal fin, which serves to deposit the sperm in the female's body.

The swim bladder in the fish is an organ which allows the fish to control its buoyancy.  The swim bladder contains air which allows the fish to float.  The fish can control the amount of air in the swim bladder.  Air is absorbed from or released into the bloodstream.

If the fish wants to sink, it absorbs the air from the bladder into the blood, the swim bladder shrinks in size and the fish sinks.  If the fish wants to rise, it releases air into the swim bladder and the fish rises.

Some fishes such as sharks and rays do not have a swim bladder.  They control their buoyancy by swimming and generating lift with their fins.

Bottom dwelling fish also do not have swim bladders.

Pregnant Fish should be handled delicately.  Pregnancy makes the fish vulnerable to predators as they cannot swim fast.  Hence, these fish should be isolated or there should be sufficient plants in the aquarium which offer seclusion and privacy.

Some Pregnant Fish can become aggressive towards other fish.  It is best to isolate such fishes in another tank.  Pregnant Fish may not be able to swim fast and may not be able to compete with other fish for food.

While feeding, ensure that the food reaches the pregnant fish.

Goldfish have relatively long lifespans amongst fish. Goldfish have been known to live for 30 to 40 years in captivity.

It is sad that many do not make it to more than a few months in aquarium.

The aquarium should be kept clean with periodic water changes.

Goldfish are social fish. They should be kept in groups of at least three. The tank should be of sufficient size to accommodate their growth.

A tank with a minimum size of 50 litres is recommended.

Spirulina is a blue green algae, originally found in volcanic lakes.  Spirulina is known for its ability to increase resistance in fishes.  This helps fishes fight infections.

It has raw proteins and almost all essential vitamin.  It is rich in fatty and amino acids as well.

Spirulina also has color enhancement properties.

Fish foods which contain Spirulina as a staple are available.  Check that that foods which claim to be spirulina based have spirulina in excess of 20%.

Fertilizer Pellets are small pellets which are placed in the substrate of planted aquariums to fertilized live plants which are planted.  Plants in an aquarium do not

ordinarily require pellets.  The Nitrates produced by the aquarium from uneaten food and fish waste is itself sufficient for the plants.

However, if the tank is new or if a large number of plants are introduced.  Fertilizer Pellets may be necessary as supplements.

Fertilizer Pellets are loaded with nutrients.  They release the nutrients slowly over a period of weeks.  Since, they are buried within the substrate, algae cannot access them.

They are ideal for rooted plants.

When fish fall sick, the most widely used method of medicating them is adding the medication to the water.  Another method of giving medicine to fish is through the use of medicated food.

Medicated Food has the advantage that it can be delivered in adequate doses quickly.  The medicine also enters the fish's body directly.

Medicated Food for fish infections are available readily in the market.  Medicated Food can also be prepared at home using special techniques.  It is necessary to ensure that the food is palatable, that the fish like its taste so that they will eat it.

Medicated Food, however, often cannot be used for fish which are very sick and do not eat.  In addition, the downside of using medicated Food in a tank is that fish which do not need medication may also eat the medicine.

Some hobbyists starve the fish for 24 hours to make them hungry and then add the medicated food.

Liquid Fertilizers are Fertilizers that are directly added to the liquid in an aquarium.  Aquatic Plants which are free floating draw their nutrients from the water.

Adding fertilizers in the form of pellets or mixing it with the substrate will not reach these plants.

Hence, the fertilizers have to be added directly to the water.  These special fertilizers contain micro-nutrients for the plants to absorb.  Some Fertilizers also contain potassium.

These Fertilizers never contain phosphates or nitrates as this can result in an algae bloom.  Nitrates can also harm the fish.

Never add household gardening fertilizers.  The high nitrate and ammonia in these fertilizers can kill fish.

Algae are microscopic plants which grow in the water.  Algae like all plants get their energy from photosynthesis.  They absorb nutrients from the water and prepare food in the presence of sunlight.  Algae play a beneficial role in the aquarium.  The serve as food for many species of fish.  They also help lower the nitrate level in the aquarium.

However, sometimes if there is too much light or too much of nutrients in the water.  The algae population can explode.  This can result in algae colonizing the aquarium tank walls and affecting visibility.

The water can turn green due to the algae.  Algae can also colonize the equipment fitted in the aquarium such as filters and other decorations.

Algae Bloom can be prevented by cutting off light and nutrients.

Do not leave the lights in the aquarium switched on for extended periods.  Ensure that partial water changes are carried out periodically.  This will ensure that excess nutrients are not available.

Having live plants in the aquarium also reduces the algae population.  This is because live plants compete with algae for the same nutrients.  The nutrient levels are thus within limits.

Ultra Violet Sterilizers which sterilize the water using an ultraviolet heat source can also be used to keep the algae population in check.

There are also special algicides which can be added to the water to control algae.

When food is added to fish.  The food may float in the surface of the water.  This makes the food available to surface fish which stay in the surface.  However, there are many species of fish which do not come to the surface.
These fish will not get food.  Hence, when feeding it is necessary to choose your food depending on the fish you have.  Sinking Food is a special type of food which sinks once it is dropped into the tank.  This ensures that middle level fish also get a chance to eat.

There are different types of sinking food depending on the rate of sinking.

If you have nocturnal fish, drop some food before switching the lights off.  This will ensure that the fish which forage at night will find food.

Topical Treatment refers to individually treating your fish by applying medicine to its body.  Topical treatment can be done for large and medium-sized fish such as Koi, Goldfish and many other species.

Topical Treatment is ideal in the case of ulcers, cuts from fights or in treating parasites.

Isolate the fish with a net. Bring it to the water's surface.  Gently lift the affected part out of the water.

Clean the surface to be treated.  Apply the disinfectant or the antibiotic to the body.  Topical medication contain gels which help the medicine bind to the fish's body for a long time.  It may be necessary to repeat the treatment once every 24 hours.

Keep the heat of the fish in the water to allow it to breathe.

Topical treatment is ideal when one fish is affected.  However, it is also necessary to identify the cause of the ulcer or parasite.  This may necessitate the treatment of the entire aquarium.

Cloudy Water in the Aquarium can be caused by a host of factors ranging from algae growth to improper filtration to excessive food.  It is necessary to find out the cause of cloudy water in an aquarium.

Cloudy aquarium affects the appearance of the aquarium and gives and unhealthy appearance.
Stock the aquarium lightly.  Excess number of fish produce waste which takes time to be broken down by the bacteria.  This can cloud the water

Do not overfeed.  Fish can only eat so much.  Feed in small amounts.  Wait for five minutes after feeding.  If the food has not been consumed.  Remove uneaten food.  The particles from uneaten food can cloud the water.

Algae can also cause cloudiness.  Algae thrive when the water has excess nutrients.  Partial water changes will help.

Aquarium Filters help filter the suspended particles in the water.  Check if your filter is working.
Regular partial water changes can reduce excess nutrients in the water.  This reduces algae growth.  Partial water changes also removes the suspended particles.  Hence, make sure that your tank gets regular water changes.

Crabs are interesting creatures.  Crabs live both in freshwater and seawater.  Hence, they can be placed in both freshwater and marine aquariums. Fiddler Crabs, Red Claw crabs are some of the common crabs housed in aquariums.

Crabs need a small area above the water line as they are semi-aquatic creatures.  Hence, many aquarists keep a huge rock which rises above the water line.  Make sure that the rock is not near the glass walls of the aquarium as the crabs can escape.

Decorations and connections to the aquarium equipment such as air tubes and wires should be carefully arrange so that the crabs do not escape from the aquarium.

Crabs eat uneaten food and keep the bottom clean.  In addition, some crabs eat snails and keep them under control.  Crabs also preen live plants in their search for food.

Flake food which sinks to the bottom are ideal for crabs.  Crabs also eat brine shrimp and worms.

Like all invertebrates, they are vulnerable to fish medication.  Therefore, remove your crabs from the aquarium before adding the medication

Fertilized Substrates are used for Planted Aquariums.  While common substrates such as gravel and sand can be used for planted aquariums, some hobbyists who seek a more rich growth of plants for their aquarium prefer Fertilized Substrates.

These substrates can be readily added to the aquarium.  They contain trace elements to nourish aquarium plants.   Some substrate have special type of soil which resemble a specific location in the wild.  Some substrates can resemble the soil of the Amazon or the soil in an ocean reef zone.

These Fertilizers can be mixed with the substrate.  Laterite is an example.  Laterite provides a source of iron for plants.  It should be placed below the substrate where the roots of the plant can reach.

Keeping it above the substrate causes it to leach into the water and cause a spike in algae.

Few things can be more sad and disappointing than the disappearance of fish without a trace.  The fish is there at night and is missing when you check the next morning.

Fish can disappear for a variety of reasons.  Some fish jump out of the water.  Jumping out of the water can be caused by poor water quality or overcrowding.

If you cannot find this fish, it is necessary to do a proper search in the tank.  Sometimes, fish which are sick may hiding in a corner or crevice.  You can treat the fish if you locate it.

Sometimes, fish die due to natural reasons and they are eaten by the other fish in the tanks.

In some other cases, fish die behind plants or other accessories such as filters.  It will be difficult to detect them in such cases.

Some times, fish which have disappeared will reappear in a few days.  They may have been hiding somewhere or may have been sick.

If there are frequent fish disappearances, you may have to suspect another fish.  Some fish may swallow or attack other fish.  You must identify such fish and remove it from the aquarium before adding new fish.

Bully Fish are fish which tease or attack other fish in your aquarium.  Such fish can injure or kill other fish.  Some may only chase other fish.  However, fish which are chased can become stressful which may result in death.

Hence, it is necessary to identify and remove fish bullies from the aquarium.

Fish bullies can be kept in a separate tank.

Adding more plants and hiding plants will help smaller fish hide.  This can sometimes solve the bullying problem.

Make sure that fish in you are adding are compatible with one another.  Some fish are aggressive by nature. It is best that you avoid them.

Make sure that all your fish have enough to eat.  Hungry fish may attack other fish or their slime coat.  Ensure that all your fish in all levels of the aquarium have access to food.

If a particular species of fish is being attacked.  Add more than one fish of the species to the tank.  This will make the bully chase the fish in turn so that no single fish will be overly stressed.

Sometimes, mating behavior can be confused as bullying.  Male guppies for instance will chase female guppies. Ensure that there is one more female than the number of males in the tank.

Fish which have laid eggs or have young can also become hostile.

Over crowding can also be a reason for bullying.  Some fish are territorial.  When their space is threatened, they can become aggressive.  Ensure that your aquarium is properly stocked.

Some fish tend to get aggressive during the mating season.

If none of these things work, you can ask your pet shop if they will take back the bully fish.  They may not return your money.  Some pet shops may give you another fish in exchange.

Constipation is a serious problem in fish. Constipation may cause other problems such as fish bladder disease and Constipation can be identified by long stringy faeces which hang behind the fish. Fish may appear bloated and disinterested.

Constipation occurs due to the lack of fiber in the food.  Fish which are fed on only one type of food such as pellet based foods or worms may develop constipation.

Changing the diet to a more varied type can prevent constipation in fish.  Aquatic plants are a good source of fibre.  It is good to have live aquatic plants in the aquarium.  Tinned peas are a good laxative for fish suffering from constipation.  Epsom Salt (Magnesium Sulphate) can also be used as a laxative.

Macro Algae are large Algae species.  Macro Algae are found in the ocean floor.  They are increasingly used in saltwater aquariums.  Macro Algae serve to absorb unwanted substances such as phosphates and nitrates from the aquarium.

They also provide a natural feel the aquarium.  They provide hiding places for fish and serve as food for herbivorous fish.

Common species of Macro Algae are Halimeda, Maiden's Hair, Caulerpa, etc.

An Aquatic Veterinarian is a vet who specializes in aquatic creatures such as fish and other inverterbrates.  An aquatic veterinarian may prove invaluable when your have an unexpected disease outbreak in a tank.

While online tips and suggests may be useful, a professional opinion and treatment schedule designed by an expert  has its own place.

Hence, it is advisable that every hobbyist gets in touch with a veterinarian in his locality.  Meet the veterinarian and talk to him.  Get details about his experience, specialization, visiting fees and facilities in his clinic.

Prompt intervention by a professional in the initial stages or an disease outbreak may save you a lot.

Aquatic Veterinarians can also make monthly visit to inspect your aquarium and evaluate parameters.

Endoparasites are parasites which live inside the fish.  Ectoparasites are parasites which live on the outer surface of the fish's body such as skin, gills, etc.

Endoparasites are relatively rare among aquarium fish.  These include worms which live in the intestines.  Endoparasites can be treated with water based medication or with medicated foods.

Ectoparasites include leeches, Fish lice and Anchorworms.  Ectoparasites can be identified easily.  Ectoparasites are usually treated with water based medication.

Slime in Fish refers to the protective layer on the fish's body.  The outer skin of fish produces glyco-protein.  This glycoprotein combines with water to produce the slime on the fish's skin.  Slime protects fish from predators by making them slippery.

Slime also protects the fish from injuries and from infections.  Slime helps heal injuries on the fish's body heal.  Slime also reduces drag and helps the fish overcome water resistance while swimming.

Slime can be damaged by the use of soap.  Never clean the aquarium or any of the equipments of the aquarium such as filters, pumps, etc. with soap.

Slime also protects fish from parasites.  In fish species, such as the Discus, a slime substance is secreted by the female to feed her babies.

The Slime coat in a fish can be damaged by poor water quality.  This makes the fish vulnerable to infections and parasites.

Handling fish incorrectly while catching can also damage the slime coat.  Unnecessary handling should be avoided.  Fish should be caughtly gently with a large net.

Parasites such as anchorworms and fish lice can also affect the slime coat.

There are medication which provide a synthetic slime coat on the fish particularly when fish are handled or netted. You can add these medication when fish are introduced into a new tank or after they have been handled.

Phosphates in an aquarium do not directly damage the fish. However, they affect the aquarium in an indirect manner. High levels of phosphates can cause a spurt in the growth of algae. Algae absorb oxygen from the water. This affects the health of the fish.

Algae growth also affects the clarity of the water and the appearance of the tank.

Uneaten food, fish waste and dead fish are the biggest source of phosphates. Keeping your tank clean is an easy way to keep phosphate levels within limits.

Planted Tanks also have lower phosphate levels and the plants absorb the phosphates and the inorganic phosphate levels are brought down.

Phosphates can be kept in check by frequent water changes. Special testing kits which measure the phosphate levels are available. However, these kits measure only the inorganic phosphates and not the organic phosphates. Organic phosphates are the phosphates which are part of the cell structure of plants and fish.

Scraping algae growth inside the tank. Rinsing the tank equipment in clean water and vacuuming the tank to remove fish waste, uneaten food and other debris can also
reduce phosphates.

Activated Carbon is used in the aquarium to absorb odors and other substances in the water such as excess medication, tannins can color the water, phenols which can create odors in the water and other impurities. Activated Carbon filters the water by the process of adsorption and absorption.

Activated Carbon, however, does not remove ammonia, nitrites or nitrates. These have to be removed only by water changes.

Activated Carbon is produced by heating carbon to high temperatures and increasing its surface area.

Absorption is the process of absorbing the toxins mechanically such as a sponge. Adsorption refers to the formation of chemical bonds between the surface atoms and
the contaminants in the aquarium water. This makes Activated Carbon very effective as a purifier.

Activated Carbon can be used to remove excess medication in the water after the fish have recovered after a treatment schedule.

Almost all the effects of activated carbon can be done with periodic water changes in the aquarium. Hence, Activated carbon is not necessary. The use and
effectiveness of Activated Carbon is still debated within the among aquarium hobbyists. Some insist that Activated Carbon "polishes" the water by making it more

Activated Carbon is available at all pet stores. Activated Carbon needs to be replaced once a month. It loses its effectiveness after it absorbs to its full capacity.

Activated Carbon should be placed after a mechanical filter in the aquarium. If there is no filter before the activated carbon, the debris will clog the carbon
surface and make it ineffective.

Can Activated Carbon be reactivated

Activated Carbon cannot be reactivated at home. In Theory, activated carbon can be reactivated at high pressure and Temperature. However, these temperatures cannot be attained at home.

Hence, carbon which has been used should be replaced with new carbon, about once a month.

Tannins are substances present in wood. In the Aquariums, tannins most come from driftwood. Tannins give a brown tinge to the aquarium water. They also slightly decrease the pH which may affect the fish.

In some cases, Tannins may be desirable as they help create the appearance a genuine ecosystem. This may be necessary in biotope aquarium which may simulate an Amazonian river where the water in some areas has a brown color.

Tannins can be removed from the aquarium by means of water changes or through the use of activated carbon in the filter.

By properly treating driftwood (Boiling and soaking), tannins can be removed prior to adding driftwood to the tank.

Baking soda is a common household Chemical.   The chemical name for baking soda is Sodium Bicarbonate.   Baking soda is sometimes used to increase the pH.  That is to make the aquarium water less acidic.

Common symptoms of low pH is nervous movement in fish.  Fish may dart across the tank.  Death of new fish which are introduced into the tank can also indicate low pH.

Common reasons for low pH are overstocking of the Aquarium and inadequate tank maintenance.

The Baking Soda should be added in small amounts.  1 teaspoon for five gallons.  Remove all the fish to a separate tank before you begin the dosage.

The pH should be changed very incrementally.  Drastic and sudden changes can kill the fish.

Brine Shrimp is a species of crustaceans which lives in saltwater.  It is a popular live food for aquarium fish.

Brine Shrimp can be cultured at home.  It is also widely available in a frozen form which can be broken and fed to fish.

There are also dried shimp and shrimp in gel form.

Infusoria is a collective term for many species of tiny organisms such as ciliates, algae and even small invertebrates which exist in fresh water bodies. Infusoria
are considered ideal food for baby fish.

Hence, many aquarists have their own infusoria culture tanks. Infusoria can be easily cultured from decomposing vegetative matter.

Place a lettuce leaf in a jar of water

Add an algae wafer

In a few days, you will see that the water is cloudy as both bacteria and infusoria establish themselves.

The cloudy water is due to the bacteria.

Over a few days, you will notice tha the water has cleared as the infusoria have eaten the bacteria.

At this point, it is possible to see minute creatures swimming in the water.

Aquarists will keep a culture of infusoria in a bottle. This culture can be used to produced infusoria when necessary in a short period of time.

Live food is the feeding of food which is alive. This includes small microscopic organisms such as infusoria, brine shrimp, nitrosomonas, etc.

Fish are always consuming live food in the aquarium in the form of algae and microscopic organisms which grow in rocks and on the glass walls of the aquarium. However, many aquarists prefer to add live food as part of the main feeding.

Common live food include worms, microscopic plants like daphnea and infusoria.  Some even resort to the controversial practice of feeding other fish such as gold fish and guppies as food.

Even common insects such as mosquito larvae, houseflies, earthworms and ants are used as food for fish.

Live food is free of preservatives and other processing chemicals.

Many aquarists culture their own live food. Worms and other microscopic foods such as infusoria, daphnea can be cultured at home. Earthworms can be cultured at home too.

Feeding you aquarium when you are on a holiday would be a matter of concern for any hobbyist. Thankfully, there are many methods to deal with this.  You can your set your mind at rest in the knowledge that your pets are given the food at the right time.

Always do a partial water change before you leave home.

Do not feed if the vacation is for a day or two
Fish can go without food in their natural environment for a week or two. If your vacation is going to be short, you can skip feeding.

Use of Holiday Food
Holiday Food is food which is made in the form of a cube which dissolves slowly releasing the food particles over a period of a few days. Both Plant-based and worm-based holiday foods are available.

Some people feel that they can cloud the water. But the water can be cleaned when you return.

Automatic Feeders
Automatic Feeders can drop food into your aquarium at pre-designated intervals. You can program these feeders to drop food into your aquarium once, twice or thrice a day depending on your aquarium's routine

Asking a friend to come over once a day.
If you have a friend or a relative living close by, you can ask them to drop in once a day to feed the fish. They can also check out on the health of the fish and inform you if anything is amiss.

Partial Water Change is one of the basic and simplest maintenance activities to be carried in an aquarium. Partial water change does not require shifting of the fish.

It does not  disturb the aquarium layout.

Partial Water Changes need to be done once in a week.
Partial Water Change involves replacing a portion of the water with fresh water.

The Steps involved in Partial Water Change are

1. Switch off lighting and other electrical appliances connected to the aquarium.

2. Remove about 25% of the water in the aquarium using a siphon (A special aquarium siphon can be used if available)

3. While removing the water, you can also use the siphon to vacuum aquarium substrate and remove decaying detritus, uneaten food and fish waste.

4. Now that the water has been removed, pour the new water into the aquarium using a funnel.

5. Pour the water so that you do not stir up the sediment or disturb the aquarium arrangement.

6. Switch on the electrical aquarium appliances such as the filter, lighting, etc.

Partial Water Changes also need to be done in case of emergency such as disease. In such cases, about 50% of the water may have to be replaced. Medication should also be added.

Ensure the the fresh water used is free of chlorine and chloramine.

Partial Water Changes also need to be done to reverse accidental overdose of medication.

Knowing the amount of water present in aquarium is essential particularly if you need to add medicine to your aquarium tank.  The dosage of medicine is critical.  The dosage depends on the amount of water.  The dosage of most medicine is calculated in litres.

To calculate the volume of the tank in litres, calculate the volume of the tank in cubic centimeters.

The volume of the tank can be calculated using simple geometric formulae such as length x breadth x height in case of rectangular aquarium or cubic aquariums.

The value in cubic centimeters should be divided by 1000.  This will give the amount of water in litres.

For instance, a tank which is 60 cms long, 30 cms wide and 30 cms high will have a volume of 54 litres.lu

Salt is sometimes used in freshwater aquariums to rid the tank of parasites or to help sick fish recover.  Common non-iodized salts available at home can be used.

Salt helps gill function.  Helps in the formation of the protective slime coating on the fish, prevention absorption of harmful nitrite.  Salt also helps get rid of  parasites.

Salt Dip

Sometimes, fish which are sick will need to be placed in a Salt Dip.  A dosage of two teaspoons to a gallon (4.5 litres) would be ideal.  The sick fish may need to be kept in a salt bath for about half an hour.

Salt Bath
A salt bath involves adding salt to aquarium itself.  This helps in treating your entire stock at the same time. However, this is not possible for all types of aquariums.  If your aquarium has live plants, the salt may damage them.  Some species of fish do not have scales such as corydoras.  These cannot tolerate salt.    Some species of tetra fish are also sensitive to salt. Do not use salt if you have such salt-sensitive species of fish.

pH is a term we come across quite often when discussing water quality. pH is the measure of the hydrogen ion concentration. The pH scale is graduated from 1 to 14.  A value less than 7 indicates that the solution is acidic while a value greater than 7 indicates that the solution is alkaline.

The lesser the value of the pH, the more acidic the solution is. Thus a ph of 4.5 is more acidic than a pH of 5.

The pH scale is a logarithmic scale which means that a water of pH 5 is 10 times more acidic than a water of pH 6

Fish are very sensitive to pH. Fish which come from rivers such as guppies and mollies are comfortable at a higher pH or a less acidic aquarium water. On the other hand, fish such as cichlids which come from the African lakes require a lower pH and a more acidic water.

Hence, when having a community tank, you must keep in mind the different pH requirement of the fish. Mixing fish with different pH requirement such as angelfish and cichlids is not a good idea.

pH can be tested with pH test strips or test kits available at your pet store. You can also buy them online.  Hand held meters are also available.

pH can be adjusted by doing partial water changes.   Partial Water Changes slightly increase the pH.

Adding shells or crushed coral as a substrate can also increase the pH as these materials contain calcium carbonate.

Zeolite is a porous absorbent mineral which is used in aquarium to absorb ammonia from the water.

Ammonia is released from fish waste and uneaten food in an aquarium.  As part of the nitrogen cycle it is broken down in to nitrites and nitrates.  However, if the nitrifying bacteria are not properly established or if more ammonia is released than usual due to excess fish in the aquarium, a dangerous ammonia spike can occur.  This can kill fish.

Hence to absorb the ammonia on a short-term basis, Zeolite is used. Zeolite acts as a sponge and absorbs the excess ammonia.  After the Zeolite is exhausted it has to be replaced.

While there are many different types of zeolites available, you must choose one which is specifically meant for aquarium use.  Further, there are different zeolite types for freshwater and saltwater aquariums.

Ammonia is a substance which is produced in the aquarium from fish waste and uneaten food.  This is a compound which is extremely toxic to fish.

This compound is broken down into Nitrite by a bacteria called nitrosomonas.  Nitrite is also harmful to fish.  Another bacteria called Nitrobacter breaks down the Nitrite into Nitrate.

These colonies of bacteria are referred to as the Biological Filters of the Aquarium.

This is called the Nitrogen Cycle. The different compounds in the cycle are Ammonia-Nitrite-Nitrate.

In a new Aquarium which has just been set up, the beneficial bacteria which break down these compounds are absent.  Hence, Ammonia can accumulate and reach dangerous levels which can be harmful to fish.  Hence, fish should be added gradually over a period of weeks.  This gives time for the bacteria to develop and colonize the aquarium.

These useful bacteria take a long time to establish themselves.  They mostly live on the aquarium gravel and the filters.  You must be careful not to damage these bacteria.

Bacteria can be damaged by the use of medication such as potassium permanganate or by washing the aquarium gravel and the accessories using soap.

Potassium Permanganate is a powerful oxidizing agent. It is also used for disinfecting water. Potassium Permanganate is caustic and dissolves the cell walls of bacteria, killing them.

Potassium Permanganate is available in the form of crystals. When these crystals are dissolved in water a pink solution is obtained.

Adding Potassium Permanganate to an aquarium kills infectious organisms. However, the downside is that Potassium Permanganate also kills the beneficial bacteria.
Hence, the biological filtration of the aquarium is affected.

Excessive doses can also damage the sensitive gill tissue of fish.

Hence, Potassium Permanganate should be used with great discretion.

Disinfecting Aquarium Plants
Potassium Permanganate is an effective substance to disinfect plants, aquarium gravel and accessories which are going to be put inside an aquarium. Immerse Plants in solution of Permanaganate for half an hour.

This will kill microbes and other harmful pests such as snails and their eggs. The plants and aquarium accessories should then rinsed thoroughly with water.

Many hobbyists love to have snails in their aquarium. Snails appear gentle and calm. Their slow and graceful movement has a soothing effect. Many snails are placed in the aquarium deliberately as part of the display.

However, too often, a small number of snails can lead to a full blown snail infestation. Snails usually eat detritus, algae and other organic matter. Sometimes, though, they can attack aquarium plants. A huge number of snails on everything from plants to aquarium walls to the grave and the filters can affect the aesthetics of the aquarium.

The Snail becomes a pest which needs to be controlled. There are different ways of controlling snails.

Commercial pesticides for Snails available at your petshop can be used. However, these pesticides tend to damage the beneficial bacterial in the aquarium affecting the biological filtration.

There are mechanical snails traps which lure the snails into an enclosure form which they cannot escape.  The snails can then be discarded.

Another method is the use of snail eating fish such as loaches and puffer fish. These fish target snails and can be effective, particularly in large aquariums.

Preventing Snail infestation

Avoid Snails
It is best to avoid snails. Many people put snails in the aquarium as part of the display. However, the snails can quickly turn into pests.

Disinfect new additions such as plants and accessories
The most common way snails enter aquariums is as eggs in plants. If the aquarium plant was previously in a tank with snails. There are chances that there are eggs in it.

The best way is to disinfect the plants by immersing them in a solution of Potassium Permanganate for half and hour. Rinse the plants thoroughly with freshwater before putting them in the tank.

A Quarantine Tank is a separate tank which every aquarium hobbyist should have. A Quarantine tank helps isolate new fish which have been brought recently. New fish can carry disease-causing microbes or parasites which can decimate your aquarium.

Hence, each new fish should be kept in observation for at least a week. Many hobbyists keep their fish for about 4 weeks as some disease take longer to manifest. If the fish are healthy after the quarantine period they are introduced into the tank.

If any fish die during this period, the water should be changed and the quarantine period for the other fish should be extended.

It is unfortunate that many aquarists neglect this important precaution and regret it later. The quarantine tank can also double as a hospital tank or a breeder tank for fry depending on the availability.

Any tank which is above 10 gallons can serve as a quarantine tank. Even an ordinary bucket can serve the purpose. Just add an air supply with an air stone.

Nitrifying bacteria are bacteria which break down the ammonia released by the fish into nitrites and then nitrates. There are a very important part of the aquarium ecosystem.   Absence of nitrifying bacteria in the aquarium can lead to ammonia or nitrite poisoning and can kill fish.

There are two main species of bacteria which are a part of the nitrogen cycle. The nitrosomonas bacteria convert the ammonia into nitrite. The other species nitrobacter convert the nitrite into nitrates.

Hence, healthy and large colonies of both these beneficial bacteria are essential for the health of an aquarium.

When the aquarium is first started, it takes time for the bacteria to establish themselves. This can be accelerated by a process called cycling where water and gravel from and established aquarium is added to the new tank. This enables the quick growth of the bacteria.

The bacteria take time to grow and hence the tank should not be loaded with fish too quickly. Add a few fish in the beginning. Later when the bacteria colonies have established themselves, more fish can be added.

Once the bacteria have established themselves, it is necessary that they are not killed accidentally. Some fish medication will kill these bacteria. An example is potassium permanganate which is used to fight infections.

Aquarium tanks and filters should also never be washed with soap. Soap can kill these bacteria.