Quick OCLT procedural question

[aquaN00b]

Hello just want to double check myself that I did this correctly. Added 10% LC at 845PM to get FC up. Tested at 1030PM...FC was 3.4. Left pump on. Tested FC again at 545AM and it was 2.8.

So FC loss of 0.6. I'm thinking this is a PASS, but is 7 hours enough time? Is pump on the entire time the correct move?

Thanks!

 

[Bama Rambler]

While technically a pass, I would run it again tonight just to make sure it's a definite pass.

 

[Leebo]

If I may toss a question back to you, why are you preforming the OCLT? Water cloudy, high chlorine demand, or just to check on things??

 

[aquaN00b]

Mostly to confirm my low FC each day is due to low CYA. My chemical demand wasn’t particularly high on re-open, but this is only my second year owning a 21,000 gallon pool. So I used Pool Math to SLAM it to around 10 FC using LC and 3 bags trichlor shock (I wanted the CYA). My awesome DE filter cleared it up in two days and it’s been crystal since labor day weekend opening. I add LC daily and when I take my readings often the sample isn't turning pink when I put the powder in. I'm using a KC-2006 kit and the CYA dot isn't fully vanishing with a full vile. So I’m just making sure low CYA is the problem. I added some trichlor 3" tabs yesterday to add FC and stabilizer, but it's slow. So my plan is to put a bunch of tabs in to sanitize and add CYA, which worked well for me last year. Once the CYA was up I switched to straight LC for the rest of the summer. I wanted to do the OCLT just to check if there's any shenanigans going on contributing to the low FC each day. Pool gets tons of sun.

This plan make sense?

 

[aquaN00b]

Did it again last night. 6.5 FC @ 1025pm and 5.5 @ 6AM. I think I'm going to add dry stabilizer today to get it up to 40 then do a SLAM to 10 FC and see how it does. I'm thinking it should drift back to normal FC by this weekend. Also, I'm getting no CC reading. That's good, right?

While technically a pass, I would run it again tonight just to make sure it's a definite pass.

 

[aquaN00b]

DOH! Forget what I wrote below. I forgot about the CYA/FC chart. Using that, I'm going to get the CYA up to 40 and the FC up to ~7 and then see how it does for a few days.

Did it again last night. 6.5 FC @ 1025pm and 5.5 @ 6AM. I think I'm going to add dry stabilizer today to get it up to 40 then do a SLAM to 10 FC and see how it does. I'm thinking it should drift back to normal FC by this weekend. Also, I'm getting no CC reading. That's good, right?

 

[Texas Splash]

You seem to have a handle on things. If 40 is your new CYA goal, then simply balance the FC according to the FC/CYA Levels and monitor. But if you decide to SLAM Process, then the FC SLAM level would be 16. Have a good day.