I'm not really sure it is the pH that is killing the fish. The Platies, the other gourami and the
CAE are doing great... eating well, swimming around, good color, I don't really see the problem.
One of the fish that died was a very small platy. I think he was being bullied by the other male platies in the tank. I didn't relize it when I bought them... but one of the platies is a female and now she looks like she might be expecting. I think the bullying had to do with his lowly status in the group.
Another fish was a dalmation molly--I really didn't even get to know that fish it was only in the tank a week and a half.
The final fish was a Dwarf Gourami. He just started hanging out at the bottom and swimming funny and then he died.
BTW when I looked at the tank pH vs tap pH... I really didn't see much of a difference. my husband thought one looked more 8 the other more 8.2ish...
I bought my fish locally so wouldn't the be used to the pH. I'm not really sure what the problem with the fish might be... just grasping at straws.