What is the most cost effective way to raise CYA? I've read somewhere to put calcuim chloride in a sock in the skimmer but can't find the article anymore on Google so not 100% that is what it said. Secondly, if this is true, where can buy this at in bulk. My CYA is 15 so need to add alot.
Second question, is it ok to run SWG with CYA at this level?