My fry are 6 and a half days old now and have not reached the free swimming stage. I don't think they will survive, but I was just wondering, what are some reasons for fry not reaching the free swimming stage? I have a high ammonia reading, but had started to water changes to lower it. The temperature is at a stable 82 degrees. Could it be genetics? The female is also quite young, around 4 months old, could that be a factor as well?