Please dont use that PH stuff it causes havoc with the water chemistry,if you are serious about breeding these fish you will need to make water of a suitable hardness and PH,to do this in hard water areas an reverse osmosis unit is essential,do some research on the net there's loads of info on there.Also a 5 foot tank is very big for breeding a 18 inch cube is the most usual size.A 5 footer would be good for a grow out tank though.