I had given up a couple years ago because I couldn't keep a coral alive here to save my life. When I lived up north I did ok. I spoke to a neighbor in my development who was having the same problem and also gave up reefing.We both attributed our failures to water quality as we are in a developing community and the TDS fluctuated between 150 and 250. I finally decided to come back this year and I've been diligent about the water quality and chasing the 0 TDS. I'm not only keeping just about everything alive I'm seeing growth! It's not cheap to change out DI resin almost monthly but I can see the results. As it stands I just received a new Membrane (75 GPD) and the manual flush valve from BRS to match the membrane. Previously I was using the flush valve for a 100 GPD and upon reading more about it I discovered that I needed to match the membrane. I hope this will increase the rejection rate coming from the membrane and in so doing give me a little more time between the DI changes?