Crushed coral is a great tool for raising the pH of your water. We use it at 1 pound of crushed coral per 10 gallons of water when mixed in with our gravel. Crushed coral dissolves continuously over time. The lower your pH is, the faster it dissolves. As the pH rises, it slows down how fast the coral dissolves. Crushed coral adds a bit of hardness to the water and it significantly boosts KH which buffers pH from swinging.
