Questions about pictus catfish.
So, I want to raise some pictus catfish (maybe 3 or 5) and I was curious about the Ph they like to live in. I have a 10 gallon tank set up outside that has some rocks that I found in a creek (testing their effect on Ph) and after about a week the rocks raised the water to 7.2. I assume it will take longer to effect the 55 gallon tank I want to keep the pictus's in, so I was wondering if a 7.2 (the maximum according to several websites) is too high? Should I avoid putting the rocks in the water? Would it be safe if I did weekly water changes? Thank you in advance.