R/O System Ph control

Are there others having a severe Ph drop from R/O systems? I am wondering if everyone uses the standard Ph Up. (potassium carbonate/potassium silicate)

Or does anyone have experience with Calcite Filters? Seen a couple of 10" Calcite filters around online.(Calcium Carbonate instead of potassium) Was wondering what the Ph increase would be on 5.9 output water. Should prevent the need for CalMag?

youll always see a drop in Ph when using RO'd water. mine goes in at 7.2 and comes out at 5.5, and like you stated I just use the standard potassium Ph up for correction. The filter your reffering too would almost certainly raise your Ph a few tenths but I see no reason it would be a supplement for cal/mg. If your using Advanced Nutrients base nutes you wont need it anyway(I think theres a couple other companies doing this now as well), but if your not I would definitely still be dosing the girls with some cal/mg. But if your looking to avoid buying cal/mg for the rest of your natural born life, and getting away from the painfully slow RO water rates, just look into some kind of a De-chlorinator, wether a filter or an additive Theres a ton of products out there. Ill be switching to a dechlorinator in the next few weeks.