Do not in anyway use chemicals to start changing your water parameters. It's a really bad idea. If your fish are happy and healthy, it doesn't matter what your water is like so long as it's constant.
Having said that, there are some organic methods of lowering your pH like adding lots of wood to the tank. HOWEVER, as I found out, this can still be problematic if have to do a large PWC. I have two large pieces of wood in my tank to create blackwater conditions it also lowers my pH to about 7.2. But if I do a PWC and replace more than about 15% of my water, my pH starts rising and that can be stressful/deadly to the fish as my tap water is at 7.8-8.0.