Didn't realize how much a tenth of pH moves my saturation index

Started by Marcus Reed · · 2 replies
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#1
Been running the LSI numbers on my pool for years just to keep an eye on scaling risk, figured a tenth of a point in pH wouldn't do much. Ran it again this week after a test and moving from 7.6 to 7.8 pushed my index from slightly negative to right at the edge of scale forming, same calcium, same alkalinity, same temp. Didn't expect that variable to carry that much weight in the equation. Makes the case for tighter pH control than I was bothering with, I was treating anything in the 7.4 to 7.8 range as basically the same pool. Not anymore, checking it more like a real input now instead of a box to check off during testing.

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#2
Yeah pH is sneaky like that in the LSI math, it doesnt feel like a big swing when youre testing but the equation doesnt care how small the number looks. Since we went salt ours tends to creep up on its own so I check it more than I used to, anyway good reminder to actually log it instead of eyeballing the range.
#3
Same story here, fill water at 400 plus calcium means I'm basically always sitting on the scale forming side no matter what pH does, so I just watch the index instead of chasing zero.