third SLAM in first season

[Jean-ji]

Our last SLAM was 9/5. We have been fine until this week when the FC started dropping more than it should. I wanted to ignore it but instead ran a OCLT. There is a 2.0 FC loss this morning. I’ve lowered the PH to 7.2

The torrential rains have eased off and the pool has been stable until this week. We got out our pool cover which was rolled up and stored out in the open in the garage last week and attached it to a roller and tried it out. We didn’t rinse it off before putting it on to see how it worked with the roller. It looked clean with no visible dirt or debris. I’m guessing that’s what started this.

After the last two slams, I’ve been keeping the FC around 10 and had just let it drift down to 7.5 to keep that as the max with 5 as the minimum in the past week.

The water is is clear, as it has been for the last two slams. Whether the water is less sparkly, Is hard to say. The FC has not dropped below 5 since the last SLAM. I’m frustrated to say the least. Any thoughts would be appreciated.

 

[Texas Splash]

Hi Jean. Well, the failed OCLT means something is eating up that chlorine. Good thing is you caught it early. Probably best to start a SLAM in hopes to wrap it up quickly. Sometimes even the clearest of water develops transparent organisms that need attention. Good luck!

 

[Steve_in_C]

During heavy rains your SWG may not be keeping up with your chlorine demands. Might help to test and manually chlorinate temporarily during these times. Looks like you are going below your chlorine minimums for your CYA.

 

[Jean-ji]

It wasn’t keeping up with rains and that was the reason for the last slam. It’s been raining, but not the water exchanging ones like before. I thought 4 min and 6 max were my targets with a CYA of 80. Should it be something else? 5 was the lowest and that was the other day, even after I upped the SWG. That’s when the alarm bells went off, the chlorine had dropped too much in one day and the SWG wasn’t keeping up when it should have been.

I started the slam early this morning and had lost 10FC by 2 pm! It’s full sun and 90 degrees today I just got home and brought it back to my SLAM target of 31. I’m hoping for a short one since I was on it pretty quick, but losing 10 seems like a lot in six hours.

 

[aussieta]

you are correct, 4 is min 6 is target..... if you can keep it there
with the rains, maybe young children etc sometimes you are dropping below
1 personally would have 6-7 min and 8-9 target with 80cya
i actually use the non swg chart because a couple of times the water lost the sparkle, but i caught it early
Pool School - Chlorine / CYA Chart
how often are you testing?, may need to test and adjust everyday when raining

 

[Jean-ji]

I’ve been testing every day and just started with every other day this week since the rains have lessened. Two prior SLAMs left me testing every day.. Chemistry was perfect on Sunday with TFC at 10.5, we brushed and vacuumed and rinsed the filter. We put the pool cover on to see how it worked and started to let the FC drift down and Kaboom! I’ll go with higher min and max from here on out., thanks!

 

[Jean-ji]

A two day SLAM did it. By late yesterday afternoon I didn’t need to add any more chlorine and it stayed steady overnight, passing all three requirements this morning. This was my shortest SLAM yet. What have I learned from three SLAMs, all with clear looking water but perhaps not quite as sparkly? If the thought even crosses my mind that the water may not be quite the same as usual, if I’m even questioning it: do an OCLT that night and know for sure. Denying what I see and taking a wait and see attitude for another day just makes for a longer SLAM. I’m catching on.

 

[Texas Splash]

Outstanding Jean!

 

[aussieta]

excellent

 

[Jean-ji]

Thanks! I’ve been properly humbled.