I use RODI water and my TDS is at 0 coming out of the unit. My salt is at 1.025, PH 8.0, Ammonia 0, Nitrite 0, Nitrate 0 and Phosphate is at 0 but I am still getting a bit of algae growth (green, red, brown and whatever is growing on my Zoanthids) and have some spirorbis popping up that I am told indicate high nutrients. I did pick up some Chemi-Pure Elite to replace my carbon with but I have not done so as of yet. I'm currently running my lights for 8 hours a day. The bulbs and actually the entire tank is approximately 3 months old. I am not feeding much because I currently have no fish in the tank (they are in a quarantine tank) and only have blue hermit crabs and snails. A lot of my Nassarius snails have gone missing (my Cerith and Margarita's I see all the time) but I would think if they were decaying my water parameters would be off. I'll try to post an whole tank pic later so you can see how much algae I have.