The liquid conditioner I used said up to 32ppm/10,000 gallons. I started around 5ppm. At the time, my pool installer had told us our pool was around 13,000 gallons which it turns out he was way wrong. By chance, I was on the manufacturer's website looking at some information about our fiberglass pool and came across the specs which indicate our pool size/model is actual 7610 gallons. I share this because it makes a huge difference in where I was going with my CYA and where I could have ended up (too high). I was already 2 months into maintaining our new pool at the time I learned of the gallon difference. Using 7610 gallons, it should have raised the CYA by 84ppm (I did rinse the bottles several times) + the 5ppm or so which would have put us around 90ppm (higher than I wanted to be, but did not know it at the time). All that being said I'm getting between 45-60 CYA readings with my Taylor kit now.
Out of curiosity I did what I believe many advise against here and took a sample to the pool store yesterday. Their results were spot on for ph and alkalinity. For CYA they got 54 (I had just got 60) so we're close there. I got 7 FC and they got 6.27 FC. For CC I got 0.5 or less using the method in which each drop = 0.5 and they got 0.46 CC. They advised me to address the 0.46 CC. I voiced I had just shocked to 20ppm 5 days ago which was determined with a CYA reading of 45 at the time (I rounded up to 50). My FC held overnight to less than 1 loss, no algae and CC of less than 0.5 so I began letting the FC come down. Pool store recommended using Fresh and Clear non-chlorine shock. I purchased 1 packet (1 pound) of it and put it in the pool. Tested water almost 24 hours later and FC now says 9 with a tinge of pink when testing the CC which goes away after adding one drop that equals 0.5ppm/drop. Took water sample to pool store again to compare results with pool stores results yesterday and my testing. Pool store says 6.68 FC and 6.68 TC so no CC. But, why is their FC 2.5ppm lower than my reading from same spot and same time? In addition, today they are reading only 24 CYA vs. their reading of 54 CYA yesterday
. They said most CYA sits within the top 6 inches of the water and is VERY sample dependent (depth, timing, location, circulation, etc.) so it's more likely the 54 CYA reading from the day before is correct.
I tend to make things more difficult than they need to be because I lean towards wanting things to be an exact science. The bottom line is I don't want anyone getting sick swimming in my pool. However, I'm feeling overwhelmed with the inconsistent CYA and CC readings. I've tested multiple times for CC using the method in which 1 drop = 0.2ppm and never have achieved a result I feel confident in because it keeps looking a shade of pink, but when I test at the same time using 1 drop = 0.5ppm it goes clear. Obviously it's ideal to have no CC in the water which could be an answer, but would likely require me to SLAM every week which doesn't really make sense.
*EDIT: Forgot to add from Taylor's website: "If monopersulfate is present in the sample it will react with DPD #3, artificially increasing the combined chlorine reading."
"Shocking" Interference I suppose this could be the reason of me getting a slight tinge of pink trying to test for CC since I had used Potassium peroxymonosulfate.
will burn off that small amount of cc’s & yes, it skews cc results (which is ironically the thing u we’re trying to remedy by using it)