kh buffer help
I have just planted my small tank. It has a gravel base and planted with 2 rotala species(rotundifolia and bonsai), some moss, and injected with pressurized co2 with ei dosing(still half dose since it's a new tank). Currently water parameters are 6.4ph(with co2), 2kh, 10gh and I use RO water with SHRIMP KING SHRIMP SALT GH+/KH+(since my tap water is BAD). Till now it only has 3 amano shrimps and a few ramhorn snail(for algae cleaning), but I would like to add some guppies. Since they like medium to hard water with ph from 6.8-7.8, I would like to add some kh to 5-6 while leaving the gh at 10, so that I can come cloase to 6.8ph or a little bit more as I think it will suite them better. I know a lot use baking soda to raise kh/ph. Is it good or is it used because it's cheap? What other additives do you suggest? Thanks.