Do you use a RO/DI unit? When i set up my tank John at Marine Oasis said our tap was good enough and he never used one so i didn't get one. Also what kind of skimmer do you run? The reason i ask is because i seem to have chronic algae problems and you obviously don't so i'm trying to isolate the source. When i start working this summer i might upgrade to T5s, upgrade my skimmer, (i have a CPR BAK-PAK) and get a RO/DI. Hopefully this little upgrade will get rid of my reoccurring algae and allow me to get a few SPS and a clam.