3degrees of kH means that in 1 week you will see your PH drop because of the nitrification process if you don’t do water changes. If you don’t want your ph to drop, do 2 water changes a week of around 50% minimum.
ic.. I am doing 25% WC on a 220 gal tank every other day. It's good to have a low pH for discus. Unfortunately, nitrate will rise as well so I would probably continue what I am doing. Thanks
