Hi, My name is Frank I have a 75gal saltwater its been up for 4 months, that I bought used. For fathers day my family bought me a yellow tang , coral beauty and I have a fox face 2clown 2 blue damsels 2yellow tail damsels and a dragon fish. They also got me a bubble tip anemone that only lasted four days, before it got caught in a power head. My point is the day after I put it in the tank my ph started fallen. Now I have done a water change of 1/3 , my calcium is 330 ,kh is 214 ph is 80. What can I do to get them back to normal? I would like to see my corals grow a little faster!