All my male fry die before maturity
I’ve been keeping guppies in this tank for a long time about two years. I have a lot of fry and all seem perfectly healthy but the last six months or so all of my male fry. end up dying early suddenly, leaving me with only one male in the tank that I got because I had no males and 20 or so females. Could my male genetic lines be bad? If it helps my ph is 7.5 my gh is 120ppm and my kh is 80ppm with all nitrogenous waste products being undetectable