Overstocking a tank

[birdma]

I am not planning on overstocking my tank but was wondering - what exactly happens when you overstock a tank? Does it really harm the fish or is it just more work to keep everyone happy & healthy? Is there ever a reason to intentionally overstock a tank?

 

[hpiguy]

The load of waste overwhelms the bio-filter and you get spikes in ammonia, nitrites and you stress, then eventually kill your fish.

You would have to stay ahead of that spike with frequent water changes.

Other issues are sometimes aggression among the fish.

 

[Cichlid Kid]

In some species of fish overstocking will cause aggression issues but in others the exact opposite will happen.
The biggest reason overstocking is frowned apon is deteriorating water quality.

 

[CorallineAlgae]

Even if a tank is well maintained the room for error gets smaller as a tank reaches full stock levels. When a tank is properly stocked, should anything unfortunate happen and the tank can't be serviced for a while, it can usually coast for a long time without to much worry about everything crashing. An overstocked tank, on the other hand, can get out of control quicker.

 

[fort384]

I would agree for the most part with the above.

I will say that what some would call overstocked, others would not, and it is all very subjective. But absolutely, the more bioload you have, the more you must be concerned with water quality issues.

 

[vanimal]

Yes an over stocked tank would need a lot more filtration and much larger more frequent water changes.

 

[Cynic]

There is two forms of overstocking.

One, too much stock. This creates bioload and potentially aggression issues. The bioload issue, depending on the severity can be managed by increased water size.

Second, too big fish. This causes stunting, shortening the lives of your fish and can not be prevented.

Generally overstocking is simply condemning your fish to a subpar life.

 

[birdma]

In some species of fish overstocking will cause aggression issues but in others the exact opposite will happen.

Kinda like people in a crowded place. Some get a little crazy and others want to go hide.

I will say that what some would call overstocked, others would not, and it is all very subjective.

Since it's subjective what is the best way for someone new to keeping an aquarium how to figure out an appropriate stocking?

 

[birdma]

There is two forms of overstocking.

One, too much stock. This creates bioload and potentially aggression issues. The bioload issue, depending on the severity can be managed by increased water size.

Second, too big fish. This causes stunting, shortening the lives of your fish and can not be prevented.

Generally overstocking is simply condemning your fish to a subpar life.

So overstocking by too many fish can possibly be solved by switching to a bigger tank?

And the too big fish thing - say you have a goldfish in a fish bowl, there's no window in which you can put him in an appropriate size tank and he'll be ok?

 

[Cynic]

So overstocking by too many fish can possibly be solved by switching to a bigger tank?

Correct. Fish size affects both bioload and aggression.

And the too big fish thing - say you have a goldfish in a fish bowl, there's no window in which you can put him in an appropriate size tank and he'll be ok?

Incorrect. Stunting occurs when a fishes growth is impeded by its environment, there is obviously a window in which growth is not impeded but it's never obvious as to what that point is.

i.e. If you put baby clown loaches in a 55G tank they are unlikely to be stunted for possibly two years despite eventually needing a 150G+ tank.

 

[birdma]

Stunting occurs when a fishes growth is impeded by its environment, there is obviously a window in which growth is not impeded but it's never obvious as to what that point is.

i.e. If you put baby clown loaches in a 55G tank they are unlikely to be stunted for possibly two years despite eventually needing a 150G+ tank.

That makes sense. I'd imagine it'd be hard to pinpoint the exact moment when a fish is no longer growing at the rate s/he should be.