400 gallon project

[Delphinus]

No kidding! Should be a matter of just testing the pH probably .. if the pH never dips below 11 it's probably just hunky-dory to do it that way.

I've never really noticed calcification inside the pump though on my reactor. But what I do notice is a buildup at the effluent line where it reacts a little with air. Having said that though, I've always felt that the kalk powder is hard on the pump. In my case I just use a MJ600 so I'm not out a lot of capital to replace it every couple of years but still, your reasoning makes me want to rethink my setup a little nonetheless.

7 seconds is awesome. It's hard to find a timer that lets you do less than 1 minute intervals. Chaulk up another advantage to using an aquarium controller...