Is it possible for high Calcium Hardness levels to cause pH rise either directly or indirectly? I've been fighting with steady pH rise for a few years now, and it appears that my CH may be around 1000, which is significantly higher than most people hit. I'm wondering if this may be leading to some sort of out-of-balance situation that ends up manifesting as pH rise. My pH goes up by about 0.2 a day or so -- enough that I have to add about a half gallon twice a week (a little less) in order to keep it in check (between 7.8 and 7.2.) I noticed on the Taylor "Watergram" wheel calculator that with such high CH, the saturation index goes out of range when the pH hits 7.8 (i.e. to about -0.7, which is beyond that -0.5 recommended limit.) How much of a "problem" is this, and could this in some way be connected to my pH rise?
I compare my situation to my neighbors, and they rarely add acid -- almost never in some cases. My pool was re-plastered about 4 years ago, so the plaster is not new. The acid demand drops a bit during the winter months, but it still requires regular acid additions.
Note that when I say my CH "may" be about 1000 I mean that its not all that easy to test due to a preponderance of pink blobbies in the water during the Taylor test. I've followed the recommendations here and on Taylor's site for reducing this problem, but the "pinkness" of the actual liquid is so pale that it makes me question when the change to blue is "really" occurring. The only "obvious" change is when I hit 40 drops (i.e. 1000 CH), but at this point the pink blobbies are also turning blue, and I'm not clear if this means I've gone too far. My best guess, however, is that my CH is 1000, and my fill water is about 100. I recently replaced about 15 inches of water, which I figure is about 25% of the pool, so the CH was even higher before.
If I can get my CH down a bit it will help put the Watergram into the acceptable range, but I'm not clear how important this is, or if this is related to the pH rise. I can drain some and refill again to get the CH down further (as well as the CYA), but if it won't help me all that much, I'd prefer to save the money on water.
Here are my specs:
22K gallon non-SWG in ground pool.
FC (range) - 4.5 to 10.5 (5.5 at the moment - when FC reaches 4.5 to 5, I add a gallon to bring it to about 10 to 10.5.)
CC - negligible
pH (range) - 7.2 to 7.8 (7.6 at the moment)
TA - 50 to 60
CYA - 60 to 70
CH - 1000
I seem to have some borates in the pool based on the Lamotte test strips, but it's hard to tell because I'm not very unfamiliar with this test, and there isn't much definition between the colored squares. In other words, I am not completely confident about the results. When I compare the pool to the fill water using the strips, however, the color is a bit different, so it appears that there may be at least "some" borates in the pool.
For chlorination I use liquid Cl (mainly Hasa 12.5%.) (I stopped using pucks a while back.)
Thanks for any feedback on this,