Hi all. I have been lurking and learning for about a month, and thought we were making great progress with the pool. Then we went on vacation, had to leave the pool on the chlorinator, and we're back at square one.
So here's the dilemma. Pre-vacation, we were scrubbing and shocking. Water was crystal clear, the clearest we've ever seen it. This is our 3rd summer in the house with the pool, previously used a pool service, and we figured out this can't be that hard. With the service water would often be cloudy between visits, and even when it was clear, it wasn't sparkling. By mid June we had the thing sparkling. It still wasn't stable - we were losing chlorine overnight, but pH, TA were stable. pH typically 7.2 or 7.8, TA a bit high around 150-180. CYA was high - initially reading 300, but we saw it dropping the longer the feeder was off and we get backflushing and replacing water in the pool. It was around 150 when we left. Hardness was around 100 and would occasionally add hardness rise to bring that up.
We come back from vacation, and we had lovely light green patches of algae on the bottom, chlorine was reading 0, although the water was relatively clear. So we go through several backflush, scrub, shock cycles, and we start to make progress. Algae is gone, chlorine is dropping overnight, but not as much as before. Seems like life is good.
We started wondering if our pool volume calculation was wrong, and even though we were shocking, because we had the wrong volume in the pool calculator, we were just nibbling around the edges and not really achieving shock level. I had estimated at 12,000 based on rough measurements, when we did more accurate measurements, we're actually closer to 20,000. To achieve shock level with our CYA, we were putting in about 360 oz of bleach, new calculation yields about 700 oz.
So in the evening, we scrub and skim and backflush and them dump in our 6 bottles of bleach. Our hardness was also really low, below 100, so we added calcium chloride to bring that up. The next morning we test the chemicals, expecting great things. Nothing. No chlorine. Zip, zilch, nada.
Urgh. We had 2 bottles of chlorine left, dumped those in the morning, which was consumed during the day. Then last night, based on the pool calculator, dumped in 6 more. Readings this morning look like they did yesterday
Any ideas on why our pool is consuming so much chlorine? Is it possible to actually overchlorinate and throw it out of whack, and did adding calcium chloride at the same time mess things up?
Thanks so much for any help you can provide. I have learned so much already.