AIBU to think this fish tank is over crowded

[Glitterunicorn]

Went to visit a close friend yesterday who has bought a fish tank for the children.

In her defense the tank was up and running for a month before adding the fish and she uses test kits.

But they have 3 very small fancy goldfish and some shrimps. She seems to think there small fish and not babies.

The tank is quite narrow but tall and it looked quite small, after looking online I have found it and it's 25 L.

The water is crystal clear and they have a filter. She mentioned that they are going to get just one more goldfish next week but could have more fish but didn't want to over fill the tank. I queried this as I used to own goldfish and i had a huge tank for only 2. I think mine was 300+ L.

She showed me a book and a leaflet from a water safe booklet and both had the same info 1 goldfish per 5L. I've had a Google and I can't find out for certain as every site I look at has different information.

Can anyone offer there knowledge here as it just doesn't sound right to me.

[Schrodingersmum]

If you go on some of the aquarium or fish magazine websites they have a tank capacity calculator which works on breed and tank volume

As I recall gold fish are quite heavy polluting fish so you may well be correct as 25L is a very small tank and not really a community tank

[maz210]

It's hugely overcrowded, her fish will end up dying.

I had a 300 litre tank with 5 fancy goldfish in it and that was probably at the limit. All mine grew to about 6 inches within a few years, I eventually had to rehome them as I couldn't clean the tank properly after I injured my back.

Unfortunately there are unscrupulous fish shops out there and irresponsible owners. While fish are so cheap there will always be people willing to replace them every few months and not realising that these are actually fish that will live upwards of ten years in the correct conditions.

[liz70]

I have a 120 litre tank and I wouldn't keep even one goldfish in it.

[TheNoodlesIncident]

I used to keep tropical fish rather than coldwater, but I think you could be right. Also the tank shape you describe will have a smaller surface area which has an impact on the amount of oxygen being reabsorbed and carbon dioxide build up. So the bigger the surface area, the more fish a tank can support. Cold water fish require more surface area than tropical do.

As an aside I once saw a man buying fish by pointing at the tanks and saying to the assistant: "I'll have one of em. And some of them. And a couple of them". Clearly hadn't bothered to do any research and check that the fish he wanted would be compatible in a community tank... (and they wouldn't have been)

[Snowydog]

Oh crickey I may have a problem on my hands here as I have a 30 litre tank I believe, with a medium and a small oranda fancy gold fish in.

I did my research before purchasing all the kit and the information sheet i was going from stated 4.5 litres per gold fish.

I got my fish from a acquatics centre that are notoriously strict with there fish and make checks before selling them. I was only allowed to buy one at a time to build the filter up.

[Slarti]

I read somewhere that you shouldn't keep goldfish at all. They would naturally grow to be quite large, much bigger than a tank could ever accommodate, so every time you've seen a goldfish in a home tank somewhere that you think is normal size for a goldfish it has actually been deformed and stunted and would have died a painful premature death because of it.

[harshbuttrue1980]

Sheer cruelty and stupidity. The fish will die as they will breathe in their own waste, and there won't be enough oxygen. Not to mention the effect on their happiness at being hardly able to exercise.