As of five days ago I had finally gotten my CH up to 225 by adding about 40 lbs. of calcium chloride (the level started at 20). I thought I wouldn't have to worry about that any more, but yesterday it was down to 175.
I know with a fiberglass pool it's not to crucial the keep the CH over 220, but I'm curious as to where that extra calcium went. Is there something even in a FB pool that will suck calcium out of the water? Maybe the sand in the filter?
BTW, I just discovered that the hose bibs I used to fill the pool initially are online AFTER my water softener, darn it! I apparently sent 22,000 gallons of water through the softener and then had to add pounds of calcium to it in the pool. Luckily the new water line they ran to my pool shed is before the softener, so that water will be straight from the well for any future fills. I plan to test it soon to see what the levels are from that faucet.