recycling water change

[burgerchow]

Just wondering if anybody else out there is re-using their reef-tank water after a water change. I do. Have a 120 reef ( mixed sps and lps )and a 55 fowlr tank. When I change water in the reef, the old water from the reef goes into the fowlr tank, and the fowlr water goes down the drain. This way I can change water for 2 tanks with only having to make 1 batch of water. By the way, the old water from my reef is perfect. Nothing wrong with it. Don't even know why I change the water, something to do I guess. ( I only change 20% once a month) The reef water won't hurt the fish in the fowlr tank.