Fish Stocking and Managing the population in Aquariums

Keeping the fish population under control is a necessary part of having a good aquarium. While it may seem difficult to get fish to breed in initial stages of an aquarium. Once the right conditions are made available, it is difficult to stop fish from breeding.

Fish breed in large numbers. Live bearers such as guppies and platies give birth to about 15 to 30 young ones while egg-laying fish such as goldfish, bettas produced hundreds of young ones.In the wild, the population is kept in check by natural predators and the scarcity of food. 

However, in the aquarium food is plentiful and predators are absent. Thus, the population will start to increase in the aquariums. Thus, there is no way of keeping the population in check. This results in overcrowding and disease.

Hence, it is necessary to control the population of the aquarium.

Methods of controlling aquarium fish population

There are several methods of keeping the population in check

Selling fish

This is one of the best ways of regulating the number of fish. This also helps you make some money out of your hobby. While newborn fry cannot be sold. Fish that are a few weeks or months old can be sold. If you have space for a few more tanks you can use them to raise the fry.

Keeping the males and females separate

This can be done only if you have more than one tank. Some hobbyists stock their tank with fish belonging to only one gender. This, however, is unnatural and can stress the fish as it disturbs the natural routine.

Introducing one or two large predator fish

Large Predator fish can eat up the small fry. This ensures that only a few number of fish survive.

Decreasing plant cover

Small fish hide in the plants. Removing the plants in your aquarium will result in the small fish getting exposed to predators.

Stocking the Aquarium evenly

Stocking your aquarium evenly is important as it ensures optimum use of the aquarium space and a pleasant viewing experience. Fish live at different levels in the water. Hence, selecting fish which occupy the top, middle and lower level of the aquarium ensures that all the fish have more space. This prevents fights and injuries.

Fish such as hatchetfish, zebra fish are top dwelling fish. Their mouths are upturned as they feed from the surface. 

Fish such as guppies, swordtails, tetras are middle level fish. They swim in the lower levels. Gouramis are also another popular middle level fish. 

Bottom dwelling fish have mouths which are turned downwards. These fish scour the bottom of the tank for food. Examples include loaches, cory catfish and the pictus catfish.

Selecting Fish and Plants for the Aquarium

Selecting Fish

The centerpiece of your aquarium are your fish.  Hence, it is important to select the type and the number of fishes carefully.

Select Fish which are sturdy and adaptable.

As a beginner who is yet to get a hang of maintaining an aquarium, it is prudent to go for species which can withstand adverse conditions.  Selecting species which are sensitive to temperature and water quality can result in death.  Species such as guppies, platys and mollies are good to start with.

Select Cheap Ones

Budgeting is important in maintaining an aquarium.  You need money to buy aquarium equipment like filters, aerators, etc.  Hence, as a beginner you can opt for fish which are inexpensive.  As a beginner it is better to spend more money on aquarium equipment which will contribute to the long term health of your aquarium.

Choose species which are not aggressive

Fishes which are aggressive can attack other fishes, get into fights and injure other fish and themselves.  You will end up with injured fish or even dead fish.  Hence, it is necessary to select species based on temperament.  Fish like Guppies, Mollies and Platys are good to begin with.

In certain species, the males cannot be kept together as they will start attacking each other.  Other species such as Tiger barbs are notorious fin rippers.  They will tear the fins of other fishes

Choose the right number of fish

The number of fish should be based on the size of the tank.  Select a number so that the individuals can have their own personal space.  This will also prevent overcrowding and fights and attacks.  Selecting too less a number will make the tank seem vacant.

Select the right size of fish

Select the right size of fish.  Species like Arrowana, gourami, etc  tend to grow big.  Such species need plenty or room.  They are not suitable for small tanks.

Choose active fish

Select fish which are active.  This will make the tank lively and help you sustain interest in the hobby.

Plants in the Aquarium

It is difficult to think of a beautiful and well designed aquarium without plants.  Plants are an integral part of any aquarium.  They help in maintaining water quality.

During the daytime, they also absorb carbon dioxide and release oxygen.  They help small fish and fry hide from other big fish and help them survive.  They add to the general beauty of the tank and can give your tank a natural appearance.

When it comes to selecting the vegatation for your aquarium, the hobbyist is faced with the choice of going for natural or artificial plants.  This is a difficult choice as both have their pros and the cons.

Natural plants grow along with the aquarium.  They lend a natural appearance to the tank. They can control nitrate levels and help in maintaining the general health of the aquarium.  The can also serve as food for some fish.

The downside is that they  give out carbon dioxide during the night.  Adding excess plants may result in the depletion of oxygen levels in the tank.  Aeration may be required. When they decay, they can cause contamination and should be removed immediately.  Live Plants can also carry parasites.  Besides, they require proper lighting to grow.

Today, artificial plants which resemble real ones are available.  These plants are easy to fix in the aquarium and require minimal care.  They can be washed once in a while.  They also do not require care like natural plants.

The downside is they are passive and do not play any role in the overall health and living processes in the aquarium.

Floating plants in the Aquarium

Floating Plants

Floating plants in the aquarium give a look which resembles a pond surface. There are many floating plants to choose from. Floating plants absorb nutrients from the water. Hence, they keep the nitrate levels in check.

If you have strong light in the aquarium, these floating plants can provide shades which provides a cool, subdued lighting effect to the aquarium.

The Roots of floating plants can also be a safe place for fish fry to hide.

Common floating plants are Pistia and Azolla carolinenensis

Tools For the Aquarium

Some Aquarists prefer to have dedicated tools for their aquarium, particularly if it has live plants. Aquarium tools are useful for trimming and pruning the plants. They can also be used to arrange gravel, remove dead fish and scrape the aquarium surfaces to remove algae.

Aquarium Tools

Different tools are available for different functions. Examples are tools such as bent scissors, tweezers, scraper etc.

Specialized Tools may be required while handling corals in marine aquariums. These tools make handling plants easy.

Removing chlorine from water for your aquarium

Chlorine is a element with the Chemical Symbol Cl.  It is added to water at your water supply utility to purify the water.  It can harm your fish.

Chlorine can be removed by dechlorinators which are available in the market.  Get a good dechlorinator. The dechlorinators convert the chlorine into harmless chloride ions.

Chlorine is volatile so leaving your water in a bucket overnight can also remove it.   Put the water in a bucket or container with a large water-to-air surface.

Some water utilities have switched from to Chloramine.   Chloramine is a compound containing chlorine and ammonia.  Chloramine stays in the water for longer periods.  It cannot be removed naturally  by keeping water overnight.  Hence, ensure that your dechlorinator can also remove chloramine.

Handling Sick Fish

Fish become sick due to a variety of reasons.  The reasons for fish becoming sick can be poor water quality, fungal and bacterial infections of the skin, disease of the internal organs such as tuberculosis, kidney failure,etc

Fish that are sick will exhibit a number of symptoms.  Some of these symptoms are change in behaviour such as rubbing against rocks, unnatural swimming movements, loss of balance.

Other diseases such as parasite infestation can cause the parasites such as lice and worms to get attached to fish skin.

It is easy to identify the disease based on the symptoms.  There are several online charts and tools which will help you narrow down on the disease based on the symptoms.  

Sick fish need to be separated from the other healthy fish in the tank.  This gives the sick fish a safe place to rest and recuperate.  It also helps quarantine the sick fish and prevents the disease from spreading.

A hospital tank is a small tank in which sick fish can be kept.  It is easy to provide medication to fish.  The water in the tank should have the same temperature as that of the main tank.  

Put in some plants in the hospital tank so that the fish gets some privacy and feels secure.  Once the fish is completely cured, it can be reintroduced into the main tank.

The water, filter and other accessories should be thoroughly cleaned before reuse.

If there is a general infestation in the tank, medication can be administered directly into the tank.  If activated carbon filters are used in the tank, they will have  to be removed as the activated carbon can remove the medication from the water making the treatment ineffective.  

Feeder Fish - An Overview

Feeder Fish are fish which are raised a food for other fish.  Some Aquarists feed live food to the fish.  Fish such as guppies, platies and gold fish which reproduce quickly and can be kept in small areas are generally used as live food. Tadpoles are also used as live food. Other fish which are not considered desirable such as female bettas are also used as live feed.

Many people consider the use of feeder fish as cruel.  Besides, they point out that fish which are raised for food are usually kept in crowded conditions and underfed.

With compromised immune systems, these fish can be carriers of disease and parasites.  They also say that almost all kinds of live food can be matched with processed food available at petstores.

Proponents of live food feel that live food brings out the natural hunting instincts in fish.  This is countered by those who say that dropping a live fish into a tank from which it has no chance of escape does not simulate the natural environment where every prey has a means of escape.

The use of live feed is thus hotly debated in hobby circles.

Flaked Food

Flaked Food is fish food which has been made into flakes.  The food is mixed and then extruded or heated which produces the layers known as flakes.  Flakes are very popular among hobbyists.  Virtually all types of fish food can be made into flakes.

The flakes are small in size and usually float in the water.  This gives time for the fish to eat them.  Flake foods are usually fortified with minerals.

The size of the flake should be suitable for the fish.  Small fish may not be able to eat large flakes.

Flake Foods usually come in sealed containers.  They usually have a best-before date.

Store Flake foods in a cool dry place.  Moisture and light should not be allowed to reach the flake foods.

Pesticides to control Snails in Aquariums

Snails can be delightful additions to your tank.  But sometimes, unwanted snails or an increase in the snail population can wreak havoc on the tank system particularly the plants.

There are chemicals which can control the snail population.  However, they destroy the good nitrifying bacteria as well, damaging the biological filtration.  Hence, these should be used only as a last resort.

Snails reproduce very fast and hence their population needs to be monitored and kept in check.  When the snail population explodes, they may have to be removed.  One easy way is to boil a lettuce leaf and immerse it in the substrate and leave it overnight.  The next morning, you will find that the snails have climbed on to the leaf to eat it.  Remove the lettuce leaf and the sails and throw it away.  Repeat this for many days till the problem is under control.

Another method is the introduction of fish which eat snails.  Several Loach species eat snails.  These will help you keep the population in check.

There are chemicals which can control the snail population.  However, they destroy the good nitrifying bacteria as well, damaging the biological filtration.

Trace Elements in the Aquarium.

Trace Elements are elements which are found in small traces in the aquatic, particularly ocean ecosystem.  These elements are required for the health and growth of aquatic creatures.

Below are some of the Trace elements and their function

Magnesium
Magnesium plays a role in the formation of the skeleton.  It also regulates the pH.  It also prevent calcium precipitation

Calcium
Calcium is an extremely important components of skeletal structures. It helps in the formation of shells for aquatic creatures such as crabs, clams, bivalves.  As animals grow, they extract the calcium from the surrounding environment.  This will deplete the calcium from the water and over time, the aquarium inhabitants will suffer deficiency.  Calcium can be supplemented by adding additives to the water.

Carbonate
Carbonate serves as a pH buffer.  It also regulates the hardness of the water, a critical parameter.  Carbonate can be added in the liquid or in the powder form.

Magnesium
Magnesium is another element which has a role in the formation of skeletal structures.  The levels of Magnesium also affects the calcium levels in the aquarium.

Hence, the magnesium levels in the aquarium should be within proper limits.  Magnesium supplements are also available in the water.

Iodine
Iodine and Iodide are important for the growth of corals and their health.  Iodine is depleted by protein skimmers, by ozone and by oxidation. It also helps prevent damage to corals from excessive light.

Iron
Iron is consumed by fishes.  Iron helps in the growth of macro algae.  Excess Iron causes an increase in micro algae and may cause an algae bloom.  Hence, iron may be needed to be removed from the water.  Iron is present in tap water. Hence, the check the iron content in the tap water before using it in your aquarium.

Social Fish - An Overview

Social fish are fish which like to be in a group.  Neon Tetras, Clown loaches are examples of such fish.  Many social fish display schooling fish which is a sight to watch.  Social fish find security and assurance when they are with other fish of their species.

Putting social fish alone in a tank will make them nervous.  This causes stress and opens the door to disease and death.

Hence, when you buy fish, try to find about the social behaviour of the fish.  Social fish should have a minimum of 4 members of the species in the tank.

Can a Pleco live with goldfish ?

Plecos are peaceful fish which live in the bottom of the tank.  Plecos can live with goldfish, provided proper precautions are taken.  Both the fishes are peaceful in general.

Goldfish tend to dirty the water quite fast as they have a higher bioload.  Any tank with goldfish should have partial water changes more frequently  The Pleco is a tropical fish which may require higher temperatures while the goldfish is a cold water fish. 

Some aquarium keepers have mentioned incidents where plecos have clasped the goldfish and have sucked at the slime coat.  This, however, is very rare.  Feed your Plecos and gold fish properly.  Plecos can be given vegetables such as cucumber, zucchini,etc. 

Also provide plenty of hiding places for the pleco to rest during the day.  They are nocturnal fish.  This reduces stress and minimizes conflict.  Another important factor you should look at is space.  Both Plecos and Goldfish can grow very big.  Housing both in a small tank creates the ground for conflict.

Ensure that both the fish have their own individual space and are well fed if you decide to keep them together. 

Can Angelfish be kept with other fish ?

Angelfish are community fish.  They can be kept with other fish.  They are a semi-aggressive species which means that they get aggressive only rarely.  Common causes for aggression are inadequate space in the tank.

Angelfish need their own space.  In large tanks, they can be kept in groups.  In relatively smaller tanks, they can be kept in pairs.  A minimum space of 30 gallons is required to accommodate angelfish.

Angelfish can get aggressive during breeding, especially when they have laid eggs. 

It is better to add angelfish to tanks when they are young and small.  They get acclimatized better. 
Angelfish have long and elaborate fins.  These fins can be attractive to fin-nipping fish such as tiger barbs.  Fighter fish (Betta) should also not be housed with Angelfish.  Both fish may get aggressive resulting in injuries. 

Why do fish jump out of the aquarium ?

Many times, aquarium lovers are shocked to see their pet fish lying dead on the floor near the aquarium.  This can be prevented by having a proper cover or a hood over the aquarium tank.
In the aquarium, fish jump due to the following reasons

Poor Water Quality.
Ensure that the water in the tank is periodically changed and that the tank has an efficient filter system. 
Poor oxygenation
Adequate oxygen levels need to be maintained by means of proper aeration. 
Chased by bully fish.
Fish can jump in order to escape from a bully fish.  Ensure that all fish are of a peaceful temperament.  See Article Handling Bully Fish

Jumping out of the tank is one of the many dangers for aquarium fish.  In the wild, fish jump to catch foods such as insects resting on overhanging branches.

Fish also jump to move to a nearby water body if the water they are living in becomes inhospitable due to low oxygen content or dries up.

Betta Fish - An Overview

Bettas, also called fighterfish in parts of South East Asia, are intelligent and beautiful fish. They are fun to watch. Their graceful movement and their beautiful finnage make for impressive display.

The scientific name for this fish, Betta Splendens actually means Beautiful Warrior. The betta is a very popular aquarium fish.

Temperament
They are also highly aggressive, particularly the males. This makes bettas mostly unsuited for community aquariums. Bettas have to be kept in a tank all to themselves. Female Bettas are also aggressive.

Female Bettas can be kept in aquariums, with fish of other species.  Make sure that the tank has plenty of space. Provide hiding places where the fish can retire to when stressed. The tanks should have lots of plants, preferably floating plants.  Female Bettas can be provoked with fish with bright finnage such as male guppies

Some aquarium keepers have large number of female bettas in large numbers say 10 or 15. In smaller numbers, they can become hostile to one another and other fish. The females will soon establish a pecking order.

Bettas are anabantids - a family of fish which can breathe air from the surface in addition to breathing through gills. The Betta fish has a special organ called the labyrinth with which it can breathe air. Bettas can survive out of water for long periods provided their skin is kept moist. In nature, Bettas are found in shallow streams and waterways and stagnant water in farms in South East Asia.

Food 
Bettas are surface feeding fish. They eat from the water surface. Bettas can be fed bloodworms, daphnia and brine shrimp. Bettas need food rich in protein and fiber to survive. There are many commercial bettas food available today fortified with nutrients which claim to improve the bettas natural coloring.

Space 
In their natural habitat, the territory of each betta fish may be several hundred square feet. Hence, Bettas should be housed in spacious containers. It is sad that many people keep Bettas in very small containers. While the fish can survive in such small areas, they will be stressed. Ensure that you Betta has adequate space.

Balanced Nutrition for Fish

Fish like all animals require food.  The food they eat should contain all the ingredients necessary for healthy growth and welbeing.  Too often, owners give only one type of food to fish.

This results in deficiencies which result in stunted growth and other abnormalities.

Healthy fish should be vigorous in motion, bright-colored with proper proportions.  Examine your fish regularly for any signs of poor nutrition.  
To provide proper nutrition, it is first necessary to understand the dietary habits of fish.  Some fish are carnivores (meat-eating).  Some are herbivores (plant-eating). While most fish are omnivores (eating both plant and animal food).

Carnivorous fish need a protein based diet. These include dried worms, shrimp, etc. Herbivorous fish require plant-based food.  Examples are Spirulina, peas, etc.

Hence, try to find out the natural food for the fish you keep.  There are different types of foods available in the market.  If you have a community aquarium, it is best to add a mixture of animal based and plant-based food.

Adding natural plants to the aquarium gives a source of food to herbivorous fish.

Another reason for poor nutrition among fish is the wrong of choice of type of food.  Fish food can be broadly categorized into floating food and sinking food.

Choose the type of food depending on the fish you have.  Surface floating food will not be accessible to fish living the middle regions or in the bottom.  These fish will become malnourished.  Sinking food which slowly sinks to the bottom gives a chance to these fish to have food.

Hence, provide a combination of floating and sinking food to your fish.  Ensure that the food are in proper size.  Small fish with their small mouths cannot handle big chunks of food. These fish will go hungry.

Can Plecos tolerate salt ?

Salt is added to aquarium to improve the slime coating of fish and to prevent parasitic infections.  Many aquarium fish tolerate salt. 

Plecos too can tolerate salt by to a very small extent about 1 tablespoon/30 gallons.

Plecos are generally more sensitive to salt than other fish. 

If you have plecos in your aquarium do not add salt to it.  The risks outweigh the benefits, if any.

Can Angelfish and Gold Fish be kept together ?

Angelfish are tropical fish while Gold fish are cold water fish.  Goldfish require much lower temperatures.  While many aquarists keep angelfish along with goldfish without any problem.  While some  aquarists successfully keep goldfish and angelfish together, sometimes angelfish can attack the goldfish resulting in death or damaged fins.  

Compatibility depends on the temperament of the individual fish. 

Goldfish also generate huge waste which can contaminate the water quickly.  This, however, can be addressed by changing the water more frequently.

Hence, it depends on the individual fish.  It is not advisable to keep the two species together.  If you must, you can try keeping them if you have a big tank where each fish can keep to its own area with lots of plants.

Platys–Factsheet

Common Name: Platy

Scientific Name: Xiphophorus maculatus

Native Range: Northern South America from western Venezuela to Guyana

Size: Males: 2.5 cms; Females up to 6 cms

Food: Platys eat a wide range of foods.  From home made grain based food to flaked foods.  They can also eat Daphnia, bloodworms and Brine Shrimp

Life Expectance: 2 to 3 years

Temperament: Peaceful

pH: 6 to 8

Temperature : Platies are tropical fish.  The recommended temperature range is 24 to 28 degrees Celsius.

Reproduction: Viviparous (Live bearers)

Sexing: Male platies have a modified anal fin known as the gonopodium.  This organ is used to transfer the sperm to the female during mating.

Why do some Goldfish Change Color ?

Gold fish sometimes change color.  Color change in goldfish can be caused b a host of factors.

Genetics may influence color change.  Some goldfish change color over the course of their lifetimes.  This has to simple do with their genes.

Lighting: The amount of lighting also has to do with color.  Goldfish which are kept in brightly lit aquariums will have brighter colors than those who live in poorly lit aquariums.

Food:  Color enhancers are natural substances which are present in nature.  Aquarium foods which contains color enhancers can help your goldfish have a bright color.    Carotenoid is an example of a natural color enhancer.

Disease: Sometimes, color change can also be due to disease or an infection.  Curing this will help your fish regain the original color.

What is Kalkwasser ?

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.

What are Carbon Dioxide Tablets ? Can they be used in planted aquariums ?

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.