First, I want to post from a thread I had last year with Chem Geek at PF:
Then I reminded Richard that I have an swg and he said:(me): " . . . my calcium is also high at 520-530. It is actually hard for me to get it to blue with the kit because the water in the tube starts globbing up as I add more reagent. I recently successfully lowered my alk from 130 to 90. My ph is hanging out in the mid 7's right now for much longer than it ever has. I have had high calcium for years now and my plaster is very smooth. I do get flakes from the returns sometimes, but the cleaner sucks those into the filter, except in the spa where I use the PoolBuster to remove them. It actually seems like there are fewer flakes this year than in previous years..."
(Chem Geek): "When you had CH of 525, TA of 130, and the pH was rising and hit 7.7, then your saturation index was around +0.6 so slight scaling was possible. With your current TA of 90 and a pH of 7.5, your saturation index is a much more manageable +0.21.
If you use a non-acidic source of chlorine such as chlorinating liquid or bleach, you can lower your TA even more if you want to, even to 50 ppm, and this should further reduce the tendency of your pool's pH to rise. You'll probably find that something like 70 ppm will be fine.
Think of this as an advantage to having a higher CH pool -- you can have a correspondingly lower TA and have calcium carbonate saturation in balance and be even better off in terms of having less pH rise."What I can't remember is if I should just leave my crystal clear pool water at a high CH level or if I should drain some with the new season. I want to make this decision now before I add salt, cya, and any energy for heating into the pool for the spring "opening." I live in CA so the pool is open all winter. These are all just considerations when the pool starts warming up and the rain is over for the year."Sorry I didn't see your signature line and notice that you had an SWG. No, you don't need to move away from your SWG -- it's fine. But you can lower your TA a little more to around 70 ppm if you want to. It will lower the pH rise a little bit more. Up to you -- if the pH rise isn't annoying where your pool is at now, then there's no need to change it"
Here were my numbers this week:
FC 1.5 (I know this is low, but so is the water temp.)
CH 580, but the end point was really violet from 520 or so.
didn't measure CYA or salt because I want to decide whether or not to dilute the water first. I don't use borates because I see warnings about pets and my dog does love to "catch" water from water guns that the kids shoot around the pool for her and I read that borates could be harmful to pets who drink the pool water.
We are about to embark on a remodel in the house and there might be some construction debris (sawdust) getting into the pool this year. I'm thinking this would just mean frequent filter cleanings, but if it will effect the water chemistry a lot too, then I would want to hold off on the drain and refill until next year. Water has gotten a little $$$ around here along with gas & electricity.
This winter, about 6 inches of fresh water were drained due to heavy rainfall. That is around what it is every winter, give or take an inch. Not much winter dilution, as the CH levels show. About 3 years ago, I drained out a couple of feet, but the pool is 10 feet at the deep end, so not much was really done then either.
If I don't drain the pool this year, can I lower the TA successfully even when the water temps are lower or do I need to wait a few weeks?