Aeration is simply that: A fountain, a sprayer, a gang of splashing 12 year old boys. It raises pH.
To reduce, in this case, use muriatic acid.
I'm not really interested in the pH--I'm looking to dose milky water with muriatic acid as it can clear it really quickly--I don't think the dry acid is as effective. But your pH needs to go up first before you can try the acid trick. You could use 20 Mule Team Borax--it's faster than aeration.
Then, use the muriatic acid to lower pH again it should clear the milky water. This, of course, assumes that excess calcium is your problem.
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