Originally Posted by earhtmother
I am *assuming* that you only have have fry in this tank. Does it have gravel? What kind of filtration? Does it have a heater? How often & how much do you feed? How often do you do water changes and how much do you change? 48 fry in a 20g is far from overloaded, I have over 50 in my 20g. Your week old fry are sound like they are stressed, partly due to age and possibly also to water conditions. Fry need only a tiny bit of food (think the size of their eye) secerla times a day. They also need water changes every 2/3 days as they are MUCH more sensitive to poor water quality and they also produce hormones which actually stunt/slow their growth.
Yes I only have fry and one apple snail in this tank, yes I have natural colored gravel, I have a sponge filter, yes I have a heater, I have an automatic feeder, it feeds four times a day I have it set small but a good amount of fry food comes out, I do a 30% water change every other day.