What exactly is your gh
? What test kit are you using or are you using test strips? What fish are you keeping?
Unless you have certain delicate fish or certain inverts generally a tanks ph/kh
doesn't need to be adjusted as most can acclimate to the levels. It's much better for ph/kh
to be stable than to try adjusting it.
If a tank has to have certain ph/kh
levels using RO
water to lower levels has to be done carefully and consistently each week so you keep levels the same. I don't suggest messing with your water unless absolutely necessary.