Several months ago I emptied ~60-70% of the pool and the post-fill CH was 350ppm. I am in Arizona and our water is hard from the tap. So this seems to be about as low as I can go.
Recently tested and am running at about 600ppm. Not sure how the CH increased, as I am only adding muriatic acid and plain bleach for chlorine: my guess is that it is from rocks my landscaper occasionally kicks in or calcium scale removed from walls/etc as it re-balanced.
The calculators say to empty the pool. I really don't want to empty most of it again, just to get to 350ppm.
I've been reading a lot online -- and the advice is always "empty the pool and refill". And every forum post or article I find then mentions something like this: "If the cause is the fill water, commercial hardness reducers or chelating agents will bond with the calcium to keep it trapped in solution."
I try searching for what these products/chemicals are, and basically can't find anything specific. They all allusively seem to mention a set of products that exist, but no mention of a specific product.
Does anyone have any recommendations? (specific links, specific products) Other advice?
Pool is 10,500 gallons, play pool, Phoenix AZ, pebble tec finish. Had it constructed is about ~2 years now.