How long for FC to drop in SWG pool

[Quickstep192]

I just got my TF Test kit and discovered that the FC results that I was getting from the old test kit were low. What was showing FC=4 on the old OTO test kit is now showing FC=9 using the FAS/DPD test using the TF test kit.

After I decrease the cell output, how long can I expect it to take for the FC to “burn off” with CYA of 70? It’s HOT and sunny here (except during thunder storms

 

[almostakeeper]

Have a pool party, that'll knock it down bigly or turn the unit off for a day. FC at 9 is on the upper reaches, but only a tad. I like to keep mine between 5 and 8 and swimming everyday I cannot tell the difference.

 

[ajw22]

With a CYA of 70 it is safe to swim up to a FC of 28. FC of 9 is no big deal and not very high. Don’t worry about it and go swim. Whenever the FC drops you will be fine.

 

[Quickstep192]

I mostly want to lower the FC level just a bit so I’m able to read FCcon the OTO test kit since it’s easier for spot checks.

 

[ajw22]

I mostly want to lower the FC level just a bit so I’m able to read FCcon the OTO test kit since it’s easier for spot checks.

As you discovered the OTO test is not very accurate. It basically tells you if chlorine is in the pool and not how much.

You really cannot dial in SWG % using the OTO test.

 

[ajw22]

With CYA of 70 your FC should be in the 5-7 range. You cannot measure that accurately with the OTO test. That is why we require the FAS/DPD test for TFP Methods.