I just bought a liquid level controller and an auto shut off from purely H20 which I think will work. It was about as cheap as the DIY set up I had with a solenoid, timer, and float switch on my last tank. Steve, does your R.O. filter feed directly into your kalk reactor, or do you fill up a reservoir with water then use a dosing pump? I specifically bought a low output R.O. filter (50 gpd) with the idea that it might feed the reactor at a slow enough rate to safely dose KW. I'll find out in a month or so when I get things set up.

Cracked tube, eh? This is why I never drill the main tube for fittings, even though everyone else seems to and I get told periodically how great it works. Did you ever see the kalk reactor I built for Gator? I think it's a pretty good design and that's what I'm building for my new tank. I'm going to have left over tube to make another skimmer or reactor (I have to buy it in 5ft sections) if you have a change of heart about the square one; I don't want to take a job away from Dan, but my guess is that he's probably pretty backed up anyway.