How Do I Know If My Tank Is Overstocked?

Fishes are the plainest sailing pets to take care of among others. You won’t have to worry about future mess and removing fragile furniture or home decors because you only need to place them in one place that doesn’t even take up too much space.

In fact, an aquarium can be a focal point to one’s house. Furthermore, keeping a fish is a great hobby that can relieve our stress after a day full of hustle and bustle.

In keeping a home aquarium, some of the things we always consider are: knowing the types of fishes we can put together in an aquarium, familiarizing ourselves with their care guides, watchful about the water level, temperature, and pH level, and of course, maintaining a healthy environment for them to live in.

Last update on 2021-10-15 / Affiliate links / Images from Amazon Product Advertising API

To achieve a healthy environment for the fishes, one of the things to avoid is overstocking our tanks. Most fishkeepers weren’t aware that they are already overstocking their aquariums. It may be:

  • An excessive number of decorations that are not even helpful for the fishes. Most of us tend to exaggerate things just to make them pleasing in our eyes.
  • And a huge population of fishes living in an aquarium that exceeds its desired limit.

It is hard to tell if your aquarium is overpopulated and overstocked, it is necessary to look out for signs for the fishes to have enough room to swim and hide at the same time. We are focused on water conditions and such to avoid fish deaths but overstocking can double or even triple fish deaths.

List of signs of an overstocked tank

Bad water condition

Having dusky water easily even after cleaning is one of the signs of an overstocked tank. If your aquarium is jammed, it just not results in bad water conditions but also increases the amount of nitrate and ammonia.

A healthy environment is crucial in a home aquarium and it starts with having clean and good water filtration. To avoid dusky water, try upgrading your filtration or lessen the fishes in a tank.

Lack of oxygen

If a fish gasps, it is an indication that there is a lack of oxygen in the tank. They breathe through their gills and continuous dispense of oxygen is required.

As it is known, a fish tank only has the desired amount of water capacity unlike the other bodies of water that can accommodate freely.  If a tank is overcrowded with fishes, there will be a shortage in the supply of oxygen.

Inadequate filtration

Check the bottom of your aquarium, if you’ve seen that there is still leftover waste left, then those are the excess that cannot be cleaned by the filter due to overstocking.

The primary role of the filter is to clean unnecessary dirt in the aquarium such as waste and poop from the fishes, lessen the presence of ammonia and nitrate and provide air for them.

If unwanted waste wasn’t removed, the water quality of the tank will be bad for the fishes that can cause stress and diseases to spread quickly.

Given that the filter on the aquarium can’t do all the cleaning, you can also do it manually where we placed the fish in a temporary place while cleaning the tank. However, the nitrate will produce rapidly since it is overstocked, frequent cleaning is advisable which is a lot of work to do and will cause stress to the fishes.

Presence of algae

All aquariums have the presence of algae, though too much of it indicates an unhealthy habitat for the fishes. Algae grow by the excess nutrients that dissolve in the water and if there is a presence of light for a long period of time.

Since having a bad water condition results in excessive discharge of nitrate and ammonia, what’s more, is it produces an increasing number of algae in the tank.

Unusual behavior

A change in a fish’s behavior is not a good indication. If prevention is not put into action, it may result in fish death.

Every species of fish has its own behavior. Some of them are the shy type of fish where they like to hide on plants and rocks, breathe on the surface from time to time, swim at the bottom and so much more.

If they no longer do those things, their habitat is no longer healthy for them to live on. There’s a tendency that they would stop eating and would only stay in one place.

Fish being stressed

An overcrowded tank is one of the causes of stress to fishes as well as the balance in the condition of the water that’s why it is crucial to maintain temperature and filtration in an aquarium.

To know if your fish feels stress, be watchful to its behavior such as loss of condition and appetite, frequent hiding, inactive movements, and fast movement of their gills.

Prone to diseases that spreads quickly

Quick spreading of diseases will happen in an overstocked tank. Some of the diseases you should look out for are bacteria infections, rotting of tail and fin, white spots, skin or gill flukes, or even a hole-in-the-head caused by parasites.

Considering that in an overstocked tank, the filtration wasn’t enough to clean the water, it includes the diseases present as well. Following that they are overcrowding, the space is very limited that will be the reason for the fast transmittance of different diseases.

May harass other fishes

In cases that the fish is hiding, chasing, and biting one another and there’s a domination of food, there’s a need to separate them. It mostly happens in an overstocked tank because there is a limited swimming place for the fishes.

Separating and giving them enough room to swim will give them a healthy environment.

Cease the desired growth of fish

This is a usual problem if a big fish is put into a small tank which is a problem about the lack of knowledge of fish needs. An overstocked tank is so alike to a small tank for there is an absence of enough space for the fish that results from stunted growth.

Never leave in mind when picking a fish to take care of and purchasing an aquarium that your fishes will eventually grow, so pick already a bigger size of aquarium that best fits for them.

How many fish can I fit in my aquarium?

Rule of Thumb

There is this rule that we often hear from pet shops and other fishkeepers, the “Rule of Thumb” which states that one inch of fish, needs 1 gallon of water.

Yet many are not fond of this rule for it only cares about the size while there are many factors to consider such as the filtration requirements, plants, and so on. This rule can only be applied to small fishes such as tetras and other tropical fishes.

Surface area rule

The surface area rule is a more advisable rule for a larger surface area indicates that you can house many fishes while a shorter tank won’t be able to sustain plenty of fishes even though it contains much more water than the larger ones.

Standard size

If you have big fishes, every 1 inch equals 2.5 gallons of water requirement. For fishes that live in cold waters, 0.5cm of adult size for 0.25 gallons of water.

Mostly in home aquariums that carry 10 gallons of water, that can generally fit 6-8 of fishes excluding whoppers. Just add 10 more gallons to fit more fishes.

The size of your aquarium can only be the identification of how many fishes can fit in there. Don’t forget that our fish will grow eventually so we must always consider their sizes.

Researching their care guides and reaching out to professionals won’t hurt because you can state to them the fish you have and if you want to adopt more, they can help you choose which fish can live in the environment your aquarium has.