cloudy Kalkwasser

I was speaking to one of my friends who was questioning me about the use of Kalkwasser – he was having trouble with the mix not settling out. I figured I would post here in case it effects anyone else

I asked him how much he was using and he said “about” 2 teaspoons per gallon – and he was making 30 gallons per batch. I told him to cut back on the kalk mix some and then test the calcium level of the kalk water mix, then I had him adjust the dosage until the calcium tested at 800. He said the mix settled out some but the kalk water was still not “clear” -- hmm, little stumped so I went to his house to mix it with him. I got the same result, which frustrated me since my mix is always clear.

I figured I would mix up another batch but only 5 gallons as to not waste his RO/DI – sure enough it settled out beautifully! So the Tupperware container he mixed in was causing him issues as the bucket worked fine – but I had no answer to him as to why ?

Just incase anyone here noticed their kalk mix is not clear – follow the testing of calcium method I said above and dial in the proper mix to your water. And if need be, consider another container.

 

Cloudness has always been pretty common and does not seem to be an issue. As for testing, Kalk is actually an official pH standard, although the actual pH varies a bit by temperature. Saturated limewater should be slightly above pH 12.5 at room temperature and that is the best way to test it. Testing calcium is inaccurate at that level though. Adding excess isn't an issue either though since only so much will dissolve, and due to the high pH, it is actually self purifying. Randy Holmes-Farley showed that impurities will tend to precipitate out of solution. Most likely the cloudyness was a bit of suspended precipitate. My guess is the tupperware container may have had a slight static charge, keeping some of the precipitate suspended. Still I think it's probably better to add too much than too little because you loose power MUCH quicker than you'd expect as you get away from the saturation point. Best practice is to make sure your saturated and let it settle overnight, usually overnight is sufficient for it to clear up, but if it isn't it should not cause any harm.

Here is a great reference on kalk for anyone interested What Your Grandmother Never Told You About Lime by Randy Holmes-Farley - Reefkeeping.com