I have the same thoughts at times. My rock is the 10 years old and full of phosphate. I keep feeding light, doing water changes, runn8ng gfo and carbon, and growing chaeto in my sump and the ha keeps growing. I have been told that at some point the phosphate will be used up but it is taking forever. I now think I should change out my substrate since it is full of po4 too. I intend to beat this son of satin at some point so I can enjoy my tank again. Read the vibrant thread. It should give you hope.It's enough to make me want out of the hobby. It's been strangling my corals.