Right now it is cheaper for me to get my water from my LFS. It is only .50 a gallon for RODI water and 1.00 a gallon for RODI premixed Saltwater. That works out to only about 20 bucks a month for my top off and partials. ultimately I will be getting a Deltec Ca Reactor, a 100Gal/day RODI unit, 24w UV unit, replace the skimmer with a Deltec Skimmer, and possibly a Kalkwasser unit. But right now this is what it is because at this point with everything on the current setup, I have close to $3000.00 tied up in it and haven't even started adding livestock. The Live Rock @7.99lb x 88lbs, 1/4hp Chiller @599.00, Tank/Stand @ 600.00 and Lights 389.99 alone set me back 2293.10. I have found out that this is not a cheap hobby like the cheap freshwater setups I have had in the past, but this is much more enjoyable. The only real problem is that it has cut into my Scuba Diving budget (Reef Tank = Less Dive Trips at least for this year)
WreckDiver
WreckDiver