SLAM Questions

MM32

Well-known member
Jun 8, 2024
74
Smithtown, NY
Pool Size
16158
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Autopilot Digital PPC1 (RC-35)
I opened my pool on Wednesday 4/30 and unfortunately had a green swamp under the cover. I’ve been SLAMming, brushing and vaccuming since it was opened and the water has been basically crystal clear since about Friday morning.. However, I failed my 3rd OCLT in a row this morning. I actually lost more chlorine last night than I had the previous 2 nights. I will say that just yesterday I really gave my skimmers a really thorough cleaning for the first time with a brush/rag, so maybe that kicked up some more algae that needed to be killed off. I do also think I saw a little algae bloom in the skimmer last night. I also backwashed/recharged my DE filter this morning. I just had a couple of questions:

1) if my water has been clear for about 48 hours, is it odd that I am still failing the OCLT?
2) I measured my cya at about 70 before I started slamming. Probably because my pool company added some when they opened it. Because I’ve had to keep my FC at such high levels, could that be effecting the OCLT or making it less accurate possibly?
3) Will backwashing my DE filter help with passing the OCLT? I would assume any algae caught in there would be dead so the answer would be no, but figured I’d ask for my knowledge.
4) My pool company added shock when they opened the pool. I tested it after they left and it was at 16ppm so I never tested the ph as I thought the test would be unreliable. If they did not adjust my ph down to 7.2 before shocking, could that affect the slam?
5) Ive had to keep my FC at very high levels due to the high CYA for days, could that be harming the pool equipment?
6) I’m close to running out of drops for my FC testing in my TF Pro Salt Kit. More should be coming on Tuesday but I may run out before then. Any advice on what to do if I run out before I get more?

Thanks as always for your help 👍
 
I opened my pool on Wednesday 4/30 and unfortunately had a green swamp under the cover. I’ve been SLAMming, brushing and vaccuming since it was opened and the water has been basically crystal clear since about Friday morning.. However, I failed my 3rd OCLT in a row this morning. I actually lost more chlorine last night than I had the previous 2 nights. I will say that just yesterday I really gave my skimmers a really thorough cleaning for the first time with a brush/rag, so maybe that kicked up some more algae that needed to be killed off. I do also think I saw a little algae bloom in the skimmer last night. I also backwashed/recharged my DE filter this morning. I just had a couple of questions:

1) if my water has been clear for about 48 hours, is it odd that I am still failing the OCLT?
2) I measured my cya at about 70 before I started slamming. Probably because my pool company added some when they opened it. Because I’ve had to keep my FC at such high levels, could that be effecting the OCLT or making it less accurate possibly?
3) Will backwashing my DE filter help with passing the OCLT? I would assume any algae caught in there would be dead so the answer would be no, but figured I’d ask for my knowledge.
4) My pool company added shock when they opened the pool. I tested it after they left and it was at 16ppm so I never tested the ph as I thought the test would be unreliable. If they did not adjust my ph down to 7.2 before shocking, could that affect the slam?
5) Ive had to keep my FC at very high levels due to the high CYA for days, could that be harming the pool equipment?
6) I’m close to running out of drops for my FC testing in my TF Pro Salt Kit. More should be coming on Tuesday but I may run out before then. Any advice on what to do if I run out before I get more?

Thanks as always for your help 👍
Your log says a bunch of your tests are coming back with the FC way over SLAM level. The farther the FC goes over SLAM level, the faster it burns off. During the SLAM, you just bring the FC “UP TO” SLAM level, not try and stay above it.

Try letting the FC come down a bit to 1/2 SLAM and do the OCLT again.
 
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First, are you doing the OCLT readings after dusk and before dawn? If so, recommend following the instructions in post #2. If that still fails, look for every last crevice, niche, and anywhere else that water can get to and thoroughly clean those places.
 
Your log says a bunch of your tests are coming back with the FC way over SLAM level. The farther the FC goes over SLAM level, the faster it burns off. During the SLAM, you just bring the FC “UP TO” SLAM level, not try and stay above it.

Try letting the FC come down a bit to 1/2 SLAM and do the OCLT again.
Thank you I will try this going forward! I had been trying to stay at or above slam level. It’s been hard because I’ve been sparing with my testing drops because I’m running out. I will test the cya now that I’ve replaced my water and go from there. Appreciate the advice.
 
First, are you doing the OCLT readings after dusk and before dawn? If so, recommend following the instructions in post #2. If that still fails, look for every last crevice, niche, and anywhere else that water can get to and thoroughly clean those places.
Thanks! Yes I have only been testing after the sun goes down and before it comes up 👍 I will still continue to try and clean every last crevice I can find. Appreciate the advice.
 
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Thank you I will try this going forward! I had been trying to stay at or above slam level. It’s been hard because I’ve been sparing with my testing drops because I’m running out. I will test the cya now that I’ve replaced my water and go from there. Appreciate the advice.
Just to be clear, when the FC comes down to about 1/2 slam level, should I add more liquid chlorine to bring it back up to slam level? Or just leave it at half and do the OCLT from there? Thanks again!
 
Just to be clear, when the FC comes down to about 1/2 slam level, should I add more liquid chlorine to bring it back up to slam level? Or just leave it at half and do the OCLT from there? Thanks again!
Just test it. The OCLT is not designed to work as well when FC is above SLAM level so just wait until it’s below SLAM level and do the test.
 
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