Today I had an RO unit installed, mainly for use on this tank, but also for drinking water.
I went with a super delux model - it’s tankless (cleaner, less maintenance), electric (which makes it pretty fast) has no remineralizing cartridge, does 800gpd, has a built in uv sterilizer and
tds meter on both the under sink housing and the faucet. It has an amazing 3gal pure to 1gal waste ratio.
It cost a lot, but money … meh! I got a plumber to install it because I needed a hole drilled in my sink and a couple of other small plumbing issues to take care of.