- Jun 11, 2018
- 388
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
I was checking my FC level today and got an odd result. I check from the same spot at roughly the same time of day(give or take an hour) and from at least a foot below the surface. Seven days ago my FC was 7.5ppm. Today, it was 2.5ppm. I do a full round of tests once a month and then as necessary when there’s a lot of drainage(rain). We haven’t had rain in a few weeks. My SWG is at 40%(it’s only just over a year old). I’m thinking this can’t be right so I get another sample from about 2-feet over and closer to a return. This sample showed my FC to be 6.5ppm. This sounds right to me as I keep my pool in the 6.5-7.5 range per the FC/CYA chart. What can explain this huge variance by moving just a foot or so over???? Do you think I did something wrong???