Parameters IMO are pretty good, just needs bumped a bit. Here's a wide guideline:
PH: 7.0 – 7.4, KH: 4 – 8, GH: 6 – 10, TDS: 100 – 180
Having no kh will cause your ph to swing. CRS can't handle kh, Tigers can.
Mineralplus, replenish, and fluval can all raise gh- but do affect TDS as well.
I use RO, but I like the clean slate to work with. Salty Shrimp is a great remineralizer that will take care of all your concerns in one swoop.