I don't see one question above.
No brand/form of chlorine holds better over the winter than the next. Once the FC in the pool is X, it's all the same.
Never waste your time again.
Lets imagine you have a certified watch. If i hand you another watch that agrees with it, it means nothing as *you* certified *them*. If I hand you a watch with a different time than yours, all it does is make you question your certified watch.
No good comes from second opinions here.
As long as you pass an
Overnight Chlorine Loss Test and have no visible traces of algae anywhere at all (even inside the skimmer or the stairs trim) then the 90 CYA is fine with the wet spring on its way. As they say 'April showers lower CYA flowers'.
*Providing you're still going SWG. Yes you'll need to run more FC but it'll hold very well with lower UV demand right now.
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Just remember to test PH at 9 or less FC, before you add the next dose of chlorine.