first off welcome to Talkingreef !!! well i would go with
ro/di for sure in a reef tank. I like this model from
Seahorse Source its a very good model and easy to use. it also comes with a
tds meter which means total dissolved solids. the lower ya can keep the
tds in the water the better your tank will do in the long run. the only issue is that ya need to treat the water and raise the
ph and such to keep from playing havic on your reef. which I am sure you all ready know.
