How to get proper GH and KH levels
So I had a water softener installed in my house when I moved in. It's been great for most purposes before I got back into the aquarium trade. I've been running a planted tank for the better part of two months and I recently decided to test GH and KH because I've been wanting to add some shrimp to it. the softened water tests at around 1-2 GH and KH as I imagined since that is supposed what softeners do.
So I plumbed in a valve before the softener today so I could use the straight "hard" water in my aquariums. I ran some tests and GH and KH are 9-10 and 5-6 respectively. Obviously this isn't ideal but better than the softened water. My plan is to cut it with RO water from our RO "drinking" water unit. I figure a 50/50 mixture would give me 5 GH and 3 KH so I figure I need to bump the KH almost double maybe triple, any ideas oh how I should go about doing this?
Other possibilities I've considered would be to get another RO unit and build something to collect it and add some saltyshrimp to add GH/KH but I'm trying to go the cheaper route here, since I've already spent quite a bit just getting back into the hobby and the wife may shut me down if I go further with this. Already got yelled at for shutting off the water to add the valve today, would like to keep from getting yelled at additionally if I can avoid it.