Raising Ph with crushed coral
Last night, I added about 3.5 cups of crushed coral into one of my Fluval 404 media baskets (filling it essentially) in the hopes of raising the Ph of in my 90 gallon tank. Without the coral - I was at 7.4. Now with the coral I'm at, well, . . .7.4. Hmmm. Do I need to give it more time? Do I need more of the coral? I do have two pieces of drift wood that while in the tank for two years are still probably leaking tannins, and lowering the Ph. I was hoping to overcome this. My Ph from the tap is 7.8. I could use Ph Up or Down, but I plan on 20% water changes weekly. Any advice?