Quote Originally Posted by Ameivaboy View Post
You should probably soak it for a while too after it dries as it will send the PH levels in your water through the roof
If I had use any other cement, I would have to do it, but the sikatop 121, is made with a special resin, who made it completely neutral and safe for fishes (normally used for drinkable water systems) once dry.

A guy on another forum made some tests with osmosis water, and the pH never change with the sikatop 121.

But your advise is important if you don't use waterproof cement like the sikatop 121. Cause effectively the cement will release limestone (not sure about the google translation for Calcaire) who will affect the pH.