Thanks Pat. I like how you think. As an IT Project Manager, I have to look for the root of a problem and often break things down like you did. The answers below:That water looks like glass. Very nice. So why the excessive FC drop overnight? You lost 3 ppm of FC last night. That is THE question.
Reagents are stored in a kitchen cabinet.
How old are your reagents? The DPD powder is from January 2019 expiring 6/23 almost used up. I just received a new one and used it to test the same sample, and FC was 18.5. The 0871 liquid is from August 2019.
Do you use a speedstir to mix the solution? No sir. I stir after 2 drops as the color gets closer, 1 drop/stir/1drop/stir. I've been looking at getting a speedstir, yes, but spending the $30 is tough, I have to admit.
If there is nothing odd with the testing process, we have to focus our efforts back to the pool and equipment. So I'll ask to confirm the following:
- When was the last time you rinsed-off the cartridges? I put in a new one on March 23rd and only have one.
- Was the water circulating (low is fine) 24/7 and during the OCLT? No. I have a single-speed pump. But I did not leave it on last night in particular.
- When was the last time you popped-off that drain cover? Never. I do make it a point to circulate water through that drain 2 or 3 times a week. Twice a week, I also circulate water through the spa jets with the air blower turned on.
- Have you checked under the skimmer lid for anything odd? Behind the weir door perhaps? Yes, and they look clean
Just looking for any clues now.