Don't do nothing until you confirm there really is a pH problem. Many apparent problems are really measurement problems rather than tank problems. This problem seems to be especially common when the aquarist is using pH test kits, rather than electronic measurement with a pH meter, but all methods can and do go wrong, and you would not want to turn a good situation into a bad one simply because a pH meter was not properly calibrated. Consequently, be sure to verify the pH reading before acting in any way. You also need to know your calcium and alkalinity readings too before acting these work hand in hand it could be the calcium or alkalinity causing the problem. The best way to raise ph naturally is to open up your aquarium so it can get fresh air I have a wood top on mine so I installed a circulation fan and I have egg crate on top of aquarium and 1/2 glass tops. Open a window when your able the outside air contains more oxygen and that will bring your ph up...Also pointing a powerhead toward the surface in your aquarium will allow more oxygen into your tank water and help raise ph.
