We purchased a house over the winter with a large IG pool; have not had a pool since I was 15, so I've been doing quite a bit of research, and have read through a great deal of the info on this forum as well as others. I got the pool opened over Memorial day weekend and some chemicals tested pretty high, so played around with those a bit over a week and finally started using the pool yesterday.
I've seen a number of posts saying to ignore pool store test results, but still wanted to share my numbers, some of there's, and confirm I'm on the right path.
pH has always been pretty good, my results comparable to store results, but my initial TA reading was about 220 compared to 186 at the store. Over the last week I've done a lot of acid, added borax (from 0 up to 30 - plan to add a little more but bought all 18 boxes they had at Target), and done a lot of aerating to try and get the TA down a bit. Today's results with pH at 7.6 has TA at about 170. I'd gotten it down to 155 (store showed 130), but did another round of acid & borax since then.
FC was testing around 16 initially, but only 11 at the store. I later found the detailed instructions on this site and with those adjustments (and adding some Chem Out) have brought my results slightly more in line with the store reading. This morning my FC reading was 8.5.
CH tests for me around 425, very close to one store, but another store came back with 275.
CYA is one of my main questions. I get a very consistent reading of 70 every time I do it, even doing the diluted then double method from the forum, but one store has tested it consistently around 100 and another I had test once came back with 137. As this appears to directly affect the FC level that we need, I want to make sure I'm on the right track. The site says it's easy to mess up, but usually going over whereas my results are well under the stores, and yet both the main store (has done 3 tests for me) and the 4 tests I've done myself are all consistent. I also see the off factor on the test listed as 15-30, which could put me at the 100 from the store. That store BTW has said nothing about increasing FC to compensate, the other (with 137 reading) said to target FC of 5-7, and the chart on this site says target 8 @ CYA of 70. So should I stick with the 70 and target FC at 5-8, or go a little higher? I'm also thinking of adding a SWG, which looks like it would benefit our high CYA as well, put us more in line with the recommended value.
- What CYA reading should I go by, any what FC should I target? With FC this high to compensate for the CYA, will it still bleach clothes, etc., or does the CYA counteract all of those properties?
- Should I continue trying to lower the TA, especially if I'm planning to add a SWG? Our well water is very high (like 350 I think), so I was going to try and target 100 initially so that it stays < 120 when adding more water.
- With the CH borderline high, should I use softened water for any refills to counteract it (our unfiltered well water is like 800)?
- Anything else I've missed?