I have a 120gal tank that I have had running for years that has started going downhill (corals not doing well, slight algae). Tank - 2 to 3" sandbed, 1/3 to 1/2 of tank is live rock, lot of muchroom corals (doing well), bubble, cactus, gorgonian, hammer, lots of coralline algae, 1 tang, 2...
