i bought a tap water purifier whan i started my tank. Its a good thing i did because in using it i found out that my tap water is terrible ( Jersey for you ). i think that it says that each cartridge should make about 80 gal of water. I can only make a little over 50. One thing i noticed about the purifier is that you have to make sure the water is coming out REAL slow. a couple of times when i went to check on my water, all the green, purple and gold particles came through the puifier and into the bucket. It just happenned the other day as a matter of fact. Sometimes it can be a pain in hte ass, but overall its a good investment. My water is pretty bad so i'm really sketchy about going from using the purifier for months, to using my tap water, which is terrible.