Too many guppies?

[Morrgan]

I have a tank of about 63 l (sorry, but I don't know what this is in gallons, if someone could help me out with this I'd be grateful) and for the past year or so, there's only been guppies in it. I don't do much about their breeding, only keep plants that the young ones can hide in. As a result, I must have more than 50 of them in there now, counting the babies too. Is this too much? The plants grow and the fish breed and are well, but that number seems awfully high...

 

[Alien Anna]

From the Melafix packet it appears that 1 US gal = 4 litres. So your tank is approx. 16 US gals.

The rule of thumb is that you should have approx. 1 inch of fish (not including tails) per 4 litres of water. This is for many reasons, but oxygenation is a major reason. By this estimate, you have approximately 3x more fish in there than the tank can support.

Not only that, but you have a significant amount of in-breeding going on as well. Inevitably, this will lead to weaker fish and I wouldn't be surprised if a catastrophe is around the corner. Fish have an annoying habit of looking perfectly healthy right up to the day they collapse down dead. You can't tell the strength of a fish's immune system just by looking at him, nor can you tell if they have internal infections, genetic disorders or cancers.

You need to start weeding out your fish. Take 2/3rds to your local pet or fish shop and donate them (or you may get a credit chit as payment). If you want a guppy species tank you ideally want no more than about 15-20 fish, including juveniles.

 

[Morrgan]

Ah, thanks for the advice. I had a feeling the situation wasn't a good one. Perhaps I should keep males only.

 

[Alien Anna]

Ah, thanks for the advice. I had a feeling the situation wasn't a good one. Perhaps I should keep males only.

That what I've decided to do, although I'm suspicious that one might be a female in drag.