Hello, we installed an 18' x 54" pool (2' in-ground) about a month ago. The water here comes from Lake Erie, and they've been having quite the time with microcystins, so who knows how that is being treated. In any case, the initial water pH was estimated at around 10 (yes, 10!) and TA was 10 as measured with Aquachek Select 541640 7-in-1 Test Strips. (Yes, I plan on getting a Taylor K-2006 at some point.) Everything else looked good.
So I added a pound of dry acid very slowly. Pool became *very* cloudy; a white precipitate settled to the bottom. Have ran pump 24/7 since opening. Tried to vacuum it up, white stuff went straight through new 75' cartridge filter. Shocked it (dichlor), making sure it wasn't anything organic, as FC = 0. Resorted to using some clarifier days later. That worked wonders, water became crystal-clear. The filter clogged (no surprise), and I rinsed out a metric ton of slimy white-blue gunk from it. Don't do this near anything valuable! Added 8lbs of Sodium Bicarbonate (all I had at the time), raising TA to about 70. Have a Pool Frog automatic chlorinator (was pushed by the salesperson... didn't know any better) and, assuming they were the experts, ran the 90-day algaecide "all-out pak", then put in the trichlor "torpedo pak", set the dial, and things were good. CYA has always read zero or close to it, so was careful to keep FC below 10 and nominally between 0.5 - 1.0 like the Frog system recommends. Kids love the pool and have used it quite a bit. The pH dropped from 7.6 to 7.4 or so during use, but was still within "ok" range. I didn't know that dichlor and trichlor lower pH before finding Pool School and the calculator! Thanks!
The "torpedo pak" (trichlor) is advertised to last about 3 weeks on average. Perhaps due to very low CYA levels, bright sun, and pool load, it expired sooner than anticipated. Several days passed with zero FC. I was away on business, and nobody else here knows to test the water, so it sat, unchlorinated, filter running on low. Water became white-murky. Tested FC, 0. Immediately threw in 4oz Dichlor Shock, assuming Frog was still chlorinating, wait. FC = 0. 4oz more dichlor, nothing. 1/2 gallon 8% bleach, nothing. Rest of 1lb dichlor bottle... nothing. Water was starting to clear, but it was in bright sun by this time, and the chlorine was disappearing faster than I could put it in. Eventually I found 12% pool bleach at Menard's, and grabbed a few. THAT finally got things under control. But "wasted" quite a bit of chlorine as whatever it was kept coming back between applications. Replaced the "torpedo pak" (trichlor.) Reset the dial. Things are good again. But now the pH is low, TA is low, CYA hasn't changed...
So I see three issues currently:
1. CYA still reads 0 or close to it.
2. pH fell from all this sudden dichlor and trichlor, 7.2 to 6.8 (yikes)
3. TA dropped from 60-ish to zero.
By my understanding, CYA should be reading much higher by now, but isn't. So I finally bought some granular stabilizer (which the pool company said I wouldn't need.) Reading the fine print, this will FURTHER reduce pH... so pH needs to be addressed first. Added a pound of Sodium Carbonate (pH Plus, "Soda Ash"), then 8oz of stabilizer. As expected, the pH went back to the "low" side after the CYA fully dissolved. That was two days ago. Know it can take time to register. Added another pound of Sodium Carbonate to bring pH back to a sane value...
So here we are today...
And I'm asking myself, is this going to be the daily rub of pool ownership? I have 16lbs of Baking Soda waiting to go in as needed to raise TA, but don't know when to do it, if the pH Plus / CYA back-and-forth is going to burn it off anyways. The girlfriend thinks I'm taking this way to seriously and should just "throw a duck into the pool and call it done."
Any advice much appreciated.