To SLAM or not to SLAM

[monsterlab]

First, my levels as of this morning:

FC 1.5
CC 0
pH 7.4 - 7.5
TA 90
CH 400
CYA 70
Salt : 3000

This is a weird one (at least to me). Over the past week or so, I've noticed that my pool is burning through chlorine at an alarming rate. I left town for a few days, and before I left, the FC level was 7. When I returned, it was pretty much 0. I immediately dumped a gallon of bleach in the pool and started watching it like a hawk.

My first thought was that the SWG was having issues, but the pool is only 4 months old, so I figured that was unlikely. Over the next few days, the FC was consistently low, and the SWG just didn't seem like it was able to keep up. The pump is running 12 hours per day, and the SWG is set to "Super Chlorinate," but at the end of the day, the FC levels have been in the 2 to 1.5 range, but the CC has always been 0, and the water is crystal clear.

I decided it was time to do an OCLT test last night. I tested around 8 PM and the FC was 3.5. At 8 AM today, it was 1.0. Water is still clear, and CC is still 0.

I should add that I live in Florida, and it has been insanely hot (mid 90's) and we've gotten a fair amount of rain. Not sure if that makes a difference, but figured it was worth adding.

Should I go ahead and SLAM? Could there be something else going on here?

If a SLAM is recommended, I have a few questions:

• It rains just about every day during the summmer. How will that affect the SLAM process?
• If it rains overnight, will that affect my OCLT results?
• Should I run the SWG while SLAMing, or just run the pump with the SWG turned off

Thanks!

 

[AimeeH]

Hi there

Your chlorine demand certainly sounds like something is up. I think I'd proceed to SLAM and assume it would go quickly since water is still clear. Rain really shouldn't have much effect of the FC levels

 

[domct203]

Hi there

Your chlorine demand certainly sounds like something is up. I think I'd proceed to SLAM and assume it would go quickly since water is still clear. Rain really shouldn't have much effect of the FC levels

Agreed. Your chlorine demand, failed OCLT, and gut feeling that something is not right are all signs that a proper SLAM is needed.

 

[monsterlab]

Thanks. Both of you basically confirmed what I was already thinking. I'm on my way to the store to buy lots of bleach.

I know it's recommended to run the pump 24/7 during the SLAM process. Should I turn off the SWG while letting the bleach do the work?

Thanks!

 

[AimeeH]

I would turn off SWG as using only liquid chlorine and testing will give you a better feel for your FC consumption.