Number of goldfish in a 40g tank?

[emerald76]

I'm in fish keeping for life and mine are fine. They have plenty of room and swim. I am
Very knowledgeable and change water once a week, half the water, I know what I'm doing. I won't change how i care for them.

Obviously you aren't as knowledgable as you think you are as you are suggesting a highly overstocked tank as a good idea and are willingly stunting your fish..

 

[0Louis0]

What kind of fish and how big are they ? What kind of filters? Ammonia should be 0, nitrite 0, nitrate below 20, ph and high range ph all depends on the fish u have. When u do water changes, rinse the filter media in the water u take out, so u won't lose bacteria. And change filter pads once a month, the carbon in the filter pad keeps the water clear, along with odors.

What's being a pain?

Kind is goldfish, fancy or not depends on which one lets me keep a lot of them.
Big I prefer like 10-15 cm but if small will do better then I don't mind.
2 powerhead filters connected to a filter box, one 1700 litre and one 2800 liters, of course the actual flow rate (not max one written) is around 2000 liters for both filters together.
I do all these water changes
The pain I meant is that their organs grow while their bodies don't, which causes them pain (which some people talked about here)

 

[0Louis0]

Obviously you aren't as knowledgable as you think you are as you are suggesting a highly overstocked tank as a good idea and are willingly stunting your fish..

Have you ever thought he can be right? I mean is there really a proof for this stunting theory? :/

 

[Samzter]

Have you ever thought he can be right? I mean is there really a proof for this stunting theory? :/

Yes, of course there is! If you want more fish you're going to have to upgrade the tank or go tropical.

 

[jlk]

Ugh just 3 or 4 goldfish in my tank makes it so empty.. not theoretically but what it looks like from outside.
I already bought a test kit, 2 strong filters and was getting ready to buy many fish and fight to keep my water clean. But this pain thing ruins it all
Cbcrash seems to have pretty long experience too, but there are so many criticizers

Perhaps you should ask the person suggesting you overstock tank about all the tank and health issues his/her fish have from keeping them inappropriately. Or read some of their posts asking why there's problems with tank/fish. Why someone would desire to intentionally harm their fish is beyond my capacity for understanding but ,ultimately, it's their decision and choice.

If you want healthy, happy fish that will live full lives stock appropriately. Those three or four fish you have now will outgrow this tank in months-not years- if you take care of them. My two largest moors have 55g to themselves for the winter and are both 10+ inches to give you a better idea.

 

[Cichlid Kid]

As it stands right now, the 4 fish you have should be ok in a 40g because they have alot of growing to do yet and as long as you do your pwc's and feed quality food trust me, they will GROW. Try to be patient and allow them to do their thing. I guarantee in a few months your aquarium will not seem empty!
To answer your question of whether stunting and organ problems really do exist? Yes, indeed. There's plenty of documentation from years of professional tests. Do a little research and see what you come up with.

Look, I know it seems like everyone's tryin to crucify you here but in reality it's the exact opposite. We want you to have a rewarding experience with this "hobby" we love and are trying to keep you from making the same mistakes some of us have made, incuding myself.
I wish you all the best and I'm sure once you study up on this overstocking issue you'll make the right choice!

 

[Mumma.of.two]

I have witnessed the results if stunted goldfish first hand. It's not pretty. Deformed bodies, elongated fins, enlarged eyes, health problems and ultimately death.
3 or even 4 small (baby) fancy goldfish would be the maximum for a 40g tank. The tank might seem empty but they will grow... a lot. If you are worried about an empty tank then add some decor and plants. If you want a tank full of fish skip the goldfish, get tetras.