I used it a little, and still have a bunch. I got into using the proper PH 8.2 and havn't had any negatives with it I can see. Be carefull, all of these Buffers are potent. I used to add what Proper said to all of my water and was always wondering why my Alk was through the roof. After I quit using it and only add once in a great while I am fine. Most of my alk control now comes from 2-part. I test my alk everyday to adjust dosage before addition to the tank. Seems to be working fine for the last six months or so.
Don't add directly to the tank if you don't have a sump, premix it.
Corals will not like any large swing in water quality be it good or bad