I live in a area with extreme KH and little GH too, so I do R/O water! It has made all the difference in the world!!! I have been using Seachem Equilibrium for quite a while, as it is for Planted Tanks, BUT it is MUCH HARDER to deal with compared to Kent R/O Right! The Seachem is hard to dissolve, and quickly hardens in the container to rocks. So I have to take some put it into a ziplock freezer bag and use a rolling pin to crush it up, or it takes a week to totally dissolve in my water storage container, a Rubbermaid "Brute" commercial grade trash can ( food safe)! So I am fixing to either switch back to R/O Right or try something else!
The "Brute" trash can is one of THE BEST investments I have made for my aquariums in a LONG LONG TIME! I have tried the cheap route and buying a normal 32g trash can, and had 1 split and spill 10g of water, then another little bit better regular trash can collapsed and spilled 30g of water in the living room flooding it, the Dinning room, and most of the kitchen in old Duplex!!!!!! Thank God it was a Concrete Slab foundation, so all we did was replace the carpet and pad! So the extra $20 or so would have saved me a LOT OF CASH in hindsite! SO either find a commercial grade food safe trash can or go to a farm supply and get a Water Tank, usually for sprayers, and you will have peace of mind! We use a Agri. water tank ( 35g) at my parents farm to haul water to the Corral when we have a Sick or Hurt Cow, and it is much better than 5g buckets! The tanks I am talking about are usually white, see through like a milk jug, and run $65 or so. I got my trash can at a Ace Hardware and it was $45 IIRC. You can even get a wheeled base to go in the bottom to make it easy to move, but they are like$75 for just the base! I use a furniture movers dolly on mine. Got it for $15 at Harbor Freight!
Anyway sorry for the rambling, but I would hate to see someone else ruin a bunch of carpet to save $20!
Well I can't wait to see how the R/O helps Ya and Your tank take shape!
Best of Luck to Ya!