Hi guys been having low PH in 20 gallon tank. Hanna red pen checker reading 7.6 and Salfert PH coming in at 7.8ish. It's in-between 7.7 and 8.0 in color range. Everything I've read online says Alk KH and Ca to raise PH but those numbers are spot on. I've raised the return more towards the top of tank to increase surface tension and have opened a window and turned on ceiling fan x2 days with no change. I'll post my logs gotta be missing something. And tests done with Salfert and Hanna checker. Ca is red sea and Mg is 2 little fishes