Why is my pool so dirty!!!

[chem geek]

If you want to have your pH closer to 7.5, then I would raise your CH level to around 300 ppm. Otherwise, you could just run your pH around 7.7 at your current CH level of 175 and be fine. It's not a big deal either way -- I'm just letting you know what is closer to ideal. Having your pH target at 7.7 would result in even less rise in pH, but if you don't see much of a rise at 7.5 and want that as your target instead, then the higher CH level would be better (but not a huge problem if you didn't do it -- the saturation index at pH 7.5, CH 175, TA 70 and CYA 20 is about -0.3).

Richard