Good size tank for guppy/molly/endler population?

[Hybrix]

Hi,

I just got into caring guppies as a serious hobby instead of just for fun and bought a bag of them with mollies and endlers from what I can tell. So currently, I have over 40 fish of several types and I'm not sure how big of a tank would be comfortable per fish population. I have about ~25 in my 80L tall cylinder, is that enough? How often should I water change? Any and every advice would be greatly appreciated.

[wandaywang]

hello, if you have a really good filter that has a high turnover rate you could really pack a tank. but obviously packed conditions would stress out fish. also, i tend to find since guppies like to be in the top level of the water, so in my opinion a longer rather than tall tank would probably suit the fish better.

i normally do 10-15% water changes once a week, taking water from the bottom of the tank. this is for a mature 100L planted tank which has a good external canister filter. without plants and with a simpler filter perhaps you might need to refresh the water more frequently.

hope this helps!