What Happens When You Overstock Goldfish Tank?

As an aquarist, you must want your goldfish to live happily. But there are several factors like overcrowding that can affect the health of your goldfish. 

So, what happens when you overstock your goldfish tank? Let us find out in the below article. 

Overstocking can stunt the growth of your goldfish. However, it can also lead to aggression in the tank, leading to severe stress in your goldfish. Overstocking can also contaminate the tank’s water lowering the tank’s oxygen level. Provide ample space in the tank for the proper growth of goldfish.

The below article will discuss the cons of overcrowding your goldfish tank. In addition, we will also discuss the measure you should take once your goldfish tank gets overstocked.

Overstocking goldfish tank

Overstocking the goldfish tank can lead to aggression and severe health issues to your goldfish.

Overstocking can affect growth and can lead to stress in your goldfish.

Overstocking can also make your goldfish aggressive towards each other while competing for food.

In addition, overcrowding can affect the tank’s water quality and lower the oxygen level, eventually making your goldfish gasp for air at the tank’s surface.

How to know that you have overstocked your goldfish tank?

Here are the ways to know that you have overstocked your goldfish tank:

  1. Aggression in your goldfish tank
  2.  Hiding
  3. Your goldfish is gasping air at the surface of the tank. 

Aggression

If you discover your goldfish being aggressive towards their tankmates, it indicates an overcrowded tank. 

Despite being non-aggressive species, your goldfish can be aggressive towards each other in an overcrowded tank due to stress and while competing for food. 

An overcrowded tank can lead to extreme aggression in your goldfish tank, leading to severe injuries to your goldfish. 

Also read: Are Goldfish Aggressive?

Hiding

Your goldfish hiding also indicates an overcrowded tank. An overcrowded tank can also make your goldfish stress making your fish hide at the tank’s bottom. 

An overcrowded tank can lead to aggression in your tank, making your goldfish hide at the tank’s bottom. 

Also read: Do Goldfish Need Hiding Places?

Gasping air at the water surface

An overcrowded tank can contaminate your tank’s water, lowering the tank’s oxygen level making your goldfish gasp air at the water surface. 

Contaminated water can further lead to severe health issues like constipation in your goldfish. 

In addition, a drop in the oxygen level can also make your goldfish suffer a lot and eventually pass away. 

Disadvantages of overstocking your goldfish tank?

Here are the disadvantages of overstocking your goldfish tank:

  1. Spike in the Ammonia Levels
  2. It affects the growth of goldfish
  3. Low Oxygen Levels
  4. Stress in goldfish

Ammonia Spike

Goldfish are messy fish that produce lots of waste as they do not have a stomach. 

An overcrowded tank can contaminate your goldfish tank’s water rapidly, leading to a spike in the ammonia level. 

A further spike in the ammonia level can make the tank’s water highly acidic, eventually affecting the gills of your goldfish. 

Ammonia spike can also lead to many other severe health issues to your goldfish leading to the passing away of your fish. 

Therefore we advise you to provide ample space to your goldfish for their proper growth and development. 

It affects the growth of your goldfish.

An overcrowded tank also affects the growth of your goldfish. Goldfish are active swimmers who require ample space in their tank for proper growth and development. 

However, placing your goldfish in an overcrowded tank will lead to extreme stress in your fish, eventually affecting the growth of your fish. 

You should always provide enough room for your goldfish to grow and develop appropriately. 

Types of GoldfishMinimum Size Maximum Size In A 10 Gallon Tank
Comet Goldfish2 inches (5.08cm) 12 inches (30.48cm)1-2 small Goldfish
Shubunkin Goldfish9 inches (22.86cm)18 inches ( 45.72cm)1 small Goldfish
Sarasa Goldfish 4 inches ( 10.16cm)14 inches ( 35.56cm)1-2 small Goldfish
Common Goldfish4 inches (10.16cm)14 inches (35.56cm)1-2 small Goldfish
Fantail Goldfish 6 inches (15.24cm) 8 inches (20.32cm)1-2 small Goldfish
The above table shows how many goldfish you can keep in a 10-Gallon Tank.

Also read: How Many Goldfish Can You Keep In A 10-Gallon Tank?

Low Oxygen Levels

An overcrowded tank can also lead to a drop in the tank’s oxygen level, eventually leading to severe health issues in your goldfish.

A drop in the oxygen level can make your goldfish suffer and gasp for air at the water surface.

In addition, it can also lead to the passing away of your goldfish.

So, it would be best to avoid always overcrowding your goldfish tank to prevent several health issues in your goldfish.

Also read: Can Goldfish Live Without Oxygen?

Stress

An overcrowded tank provides no room for your goldfish leading to stress in your fish.

Stress can also make your goldfish suffer from severe health issues and can even lead to the passing away of your fish.

Therefore, you should always provide a good size tank to avoid stress and for the well-being of your goldfish.

Also read: What To Do If My Goldfish Is Stressed?

What to do if your goldfish tank is overstocked?

Goldfish can grow up to 14 inches in captivity if you place them in a good-sized tank and under favorable water conditions. 

So, it will be advisable to shift your goldfish to a good size tank as soon as you discover that your goldfish tank is overstocked. 

Goldfish are active swimmers who require a good size tank for proper growth and development. 

But, until you arrange a more significant size tank for your goldfish, you should take the following measures to avoid any health issues in your fish. 

  1. Perform regular water changes to avoid any spike of harmful chemicals in the water. 
  2. It will be advisable to remove any large-sized hiding ornaments from the tank as they take enough space. 
  3. Keep eyeing the ammonia and nitrite levels in the tank for the well-being of your fish.
  4. Consider placing your fish in an alternative tank if you have any, or you can also put them in large containers such as plastic storage tubs. You must ensure that they are safe and watertight. 
  5. You can also transfer your fish to your friend’s aquarium until you get a good-sized tank for them. However, you must ensure that your fish gets paired with tankmates that are non-aggressive and require similar tank requirements.

Conclusion:

  1. Overstocking can lead to severe health issues in your goldfish.
  2. Your goldfish showing aggressive behavior, hiding at the tank’s bottom, or gasping air at the water’s surface indicates overcrowding.
  3. Low oxygen levels, the stress in goldfish, and the ammonia levels spike are some disadvantages of an overcrowded tank.
  4. It will be advisable to place your goldfish in a good-sized tank once you discover that your fish tank is overstocked.
  5. Therefore, always ensure ample space for your goldfish for their proper growth and development. 

Reference: ResearchGate ScienceDirect

Recent Posts