I wish I knew, but unfortunately Ive never tested for ph. It was never my intention to breed my bolivians, and it kinda just happened. My tank is heavily planted, and temps at 80 degrees. I believe the warm water encourages breeding. Its funny because I had a 29 gallon with a couple angelfish, and as soon as I put them in the 40 gallon they started breeding. I guess thats why they call it a 40 gallon breeder tank. Im keeping my fingers crossed, and hoping this goes well.