Is it common to have low CH constantly? I seem to have a lot of trouble maintaining CH. This year I started out with around 90 but I'm pretty sure we closed around 200. Seems like every year I have to add a butt load of CH at the beginning of the year. My pool is not covered over the winter and I do a few backwash during the winter due to rain water but didn't think I've drained over 50% of my water during the winter.