@brownie64 you bring up a good point and I guess I had never considered that... I know after coming out of the RO/DI the water has nothing in it... And is too pure for a freshwater tank... Basically being a clean slate to add salt mix to replenish minerals and make a perfect ocean water... I've had my guy now for 3 going on 4 months (still need to make an introduction to the forum thread

) and that is all I have been using... I'm by no means an expert on this but can't say I have noticed anything abnormal to date... The plants and everything else are growing (but I guess they take minerals from their soil) It would be nice for someone to chime in on either side of this that has had experience good or bad... And I guess I'll be looking into a way to add some kind of splitter before the DI stage so I can have RO for the chameleon and RO/DI for the reef...
I'm no expert on R.O. systems either just going by some research I did online. Like I told Carlton Some say it takes minerals out of the body, and about just as many say it don't so why take the chance. I do think the general consensus is not to drink it that's why the sell the R.O. systems as duel use "drinking and aquarium use"