OCLT results - guessing I need to SLAM?

[BlueWRXPride]

I'm pretty new here, and I think I know what I need to do, but wanted to check here before doing so.

This is my first season with a pool, and so far the water balancing has been going great. Everything has stayed pretty much right where it needs. Despite that I have felt my water clarity while good, isn't quite as good as my father-in-law's pool, but I didn't really look into it since my FC, CC, CYA, TA, and PH were all good.
Just recently I detected 0.5 ppm for CC recently, (FC 2.5, CC 0.5, PH 7.5, TA 80, CYA 50) so I decided add some chlorine and run a OCLT. I know my CYA is low, but I figured I'd wait to bump it up in case I need to SLAM it. Last night I measured my FC at 5ppm and CC at 0.5ppm, and this morning it was at FC 3.5 and CC 0.5. The OCLT says that a loss of more than 1.0 FC, and CC over 0.5 call for a SLAM. I'm right on the border, but I'm guessing that will be the recommendation here.

Assuming yes, is it ok to do a SLAM with my solar cover on? And is it ok to swim while SLAMing? Based on my CYA, I'd be getting my FC up to 20.

 

[Texas Splash]

You can swim during the SLAM as long as you don't exceed the correct FC SLAM level - in your case with a CYA of 50, your FC level needs to be 20. As long as you don't exceed 20, you can swim. Be sure to lower the pH to about 7.2 before increasing the FC. I suspect the drop in your FC was the cause of the hazy water and failing OCLT. Hopefully you got it soon enough to where your SLAM Process won't be too long.

Good luck!

 

[Newdude]

Hey Blue !!! You got it. SLAM Process

you also did well keeping the CYA lower for less SLAM FC.

Your cover can stay on but open it once a day to let the CCs burn off for an hour or so.

Swimming is totally safe between minimum and SLAM level. So long as you can see the bottom for locating disabled swimmers.

 

[drsipe]

My advice would be that if you think you might need a SLAM, then you need a SLAM. The good part is that it sounds like you caught it early, so this SLAM may go quickly. One thing that is not in your signature is how you are testing your water, and how you chlorinate. To perform the SLAM properly, you need a reliable test kit.

SLAMing with the solar cover on should be OK, but you will need to take it off periodically to allow off-gassing of the chloramines. For me, even though you will lose more chlorine to UV with the solar cover off, I would SLAM without the solar cover.

According to the CYA/chlorine chart, you are correct 20 ppm of chlorine is your SLAM level, and swimming is safe up to SLAM level, as long as you can see the bottom of the pool.

With any luck, you caught this early and the SLAM will be short.

 

[BlueWRXPride]

Yeah I have a TF-100 kit, so I'm all set there. And I use an Autopilot SWG.

Why do you need to have the PH down to 7.2 from 7.5? I saw it says that in the SLAM instructions, but it doesn't say why that's important.
Also, the instructions say to add the chlorine slowly. That means I can still add all the chlorine I need in one shot, I just want to pour it in slowly, right?

 

[drsipe]

Great, you have a good test kit.

You drop the PH because, once the chlorine level is greater than 10 ppm, the PH test is inaccurate. If you start at 7.2, adding the chlorine will not drop your PH, and the PH should not raise greater than 8.0.

Yes add all the liquid chlorine at one time that you need, the reason to pour slowly is so the you get a better mix.

One more piece of advice, algae likes to hide in unsuspected areas. If you have a ladder, or anything else in the pool, remove it and scrub it with a mixture of bleach and water. Also, if you have problems passing the overnight chlorine loss test, look at places like light niches. If you want to be preemptive, you can pull the light and set it on the pool deck (scrub it with the bleach & water mixtures) during the SLAM.

 

[BlueWRXPride]

Ok, last question. I'm going out of town in 5 days, and I'll be gone a week. Should I wait until I get back to do this? Or am I pretty safe that I can complete this before I go?

 

[drsipe]

That's a difficult question to answer. I can't guarantee, that it will be complete in 5 days, but again, if it were me I would begin right now, and it it's not complete when you leave, turn your SWG to 100% while you are gone, and then continue the SLAM when you return.