Well everything is relative Jack L for a fish that comes from an environment where the PH is around 4-4.5...7 is quite high
yes on the PH scale 7 is neutral
Filip Zebec: The question is do you want them to live or thrive. I've spent the last couple of months reading through the 10 pages of this section. One thing that does pop up is that they really seem to have better colors at a low PH. Plus we all know now that most Heckels breed at a very low PH... this tells us a lot. One variant doesn't and that's the *Rio Abacaxis. They come from waters of a higher ph.
The answer to your question is yes they can live in a ph of 7... for many years... I've kept heckel 10 years ago in such water for a few years.
My new batch will be kept in a PH of 4-4.5... why ? Because tgats the water they come from . I want to grow them out and try to have them breed when they mature. For that I need them to thrive.
Cheers
Fred