SLAM in progress

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Smitty24

0
Jun 9, 2015
22
Corpus Christi, TX
I finally got started doing a SLAM on my pool and have a question about how quickly the chlorine level should be dropping. I'll begin with sharing my beginning test numbers and my current ones.

March 27th, initial test before SLAM:
0ppm FC
0ppm CC
525ppm CH
TA 80
CYA 100

Replaced 40-50% of water to try and lower CYA and CH.

March 28th
0ppm FC
0ppm CC
300ppm CH
TA 80
CYA 50

Started the SLAM yesterday by adding 3.5 gallons of regular 8.25% Clorox to hit my target level of 20ppm FC. Apparently my pool is smaller than I thought and I over shot a bit, landing at 25.5ppm FC. This was last night at 9:00PM. Woke up this morning to check levels, expecting to see a big drop off, but my numbers at 7:00AM were 24.5ppm FC, 0.5ppm CC. I've checked throughout the day, and my last numbers at 4:00PM were 23ppm FC, 0.5ppm CC. My pool is very green. My wife thinks it looks like pea soup, and she's not wrong. With this amount of algae and contaminants, shouldn't my chlorine levels be dropping a bit faster? Or am I doing ok and just need to stay the course? I'll try to attach a pic for a visual reference. Thanks for any and all help! I'm ashamed of how terrible the pool has become. I was a die hard maintainer, nothing but bleach and muriatic acid, but over the winter I had a couple knee surgeries and we wound up using some pucks and a floater left over from the previous owner. Now we're paying the price! Lesson learned....

Picture link:
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I think you have some duplicate text. I'll let you clean it up when you get a chance.

YES! I think your FC should be consumed faster although....
1. Your pool is not horrible, it'll clean up nicely and

2. There really is no alternative.

You obviously have been reading and you get the concepts.....you just need your chlorine to get to work!

I would watch it 24 more hours and then tell us what it is doing.

Are you running the pump 24/7?

Are you brushing, vacuuming? Doing everything you can to stir the algae up into the chlorinated water to be killed?
 
Thanks Duraleigh, I thought I was doing everything right but it's always good to hear it from someone else just to be sure. I am running the pump 24/7, and I've brushed the pool twice so far, as well as running our robot almost continually in an effort to keep everything from settling. I'll keep doing what I'm doing and hupefully soon the chlorine will start doing its job. Thanks again!
 
Analogbytes said:
What was your pH when you started?
Click to expand...

Great question! Friendly note that PH reading doesn't count if FC is higher than 10. Let FC drop under 10 and then test PH. Post results. Additionally, chlorine effectiveness really drops off at ph above like 7.8 I think and anything above 8.2 is outside of the range chlorine where chlorine is an effective sanitizer. PH of 7.2 to being SLAM is ideal. Real answers covered in https://www.troublefreepool.com/content/123-abc-of-pool-water-chemistry

Final thought, the longer it was without chlorine, the harder it can be to get it to hold FC. Sometimes it is algae, sometimes ammonia, and sometimes you've got three feet of organic matter at the bottom. Okay, maybe an inch or two... Test the FC & PH and let's go from there :)
 
Sorry, I totally forgot to include my pH! It was 7.2 at the start of the SLAM. There's no organic matter in the pool to speak of, I've kept it pretty clean all winter long. I noticed some algae on the walls and floor after being out of town a couple weeks, so I went ahead and brushed everything. This made the pool pretty dirty looking but I wasn't too worried, but within a couple days it turned into the mess I've got now. I'm about to go brush it now and do another FC test so I'll post my results as soon as I'm done.
 
Just tested FC and CC after a thorough brushing, and this morning FC was down to 18ppm (from 23) but my CC is still at 0.5ppm. At least it seems like some of the chlorine was used, so hopefully it'll start going good now. I added the recommended amount of bleach to get my FC back up to 20. I took a couple more pics so y'all can see what it looks like. Thanks for all the support!

IMG_4037.jpg
 
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duraleigh said:
Chlorine is not quite as effective but only by a VERY VERY small percentage. I think OP may have a testing error (we'll see) but his starting pH is not part of the problem unless it is something TOTALLY out of range.
Click to expand...

Thanks for this info. I just remember reading that pH at 7.2 was important when starting SLAM. Maybe some of the importance is also the fact that you won't be able to get a reading on it once you start.
 

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Thanks for this info. I just remember reading that pH at 7.2 was important when starting SLAM.
Click to expand...
I would say that pH of 7.2 is maybe a little too precise. Having a pH in the 7's is all you are looking for. Two things to consider.

1. The addition of chlorine in the pool TEMPORARILY raises the pH. Not long enough or high enough for any concern, though. The addition of chlorine into a pool is a pH neutral event in the longer term.

2. Since the pH is skewed in 10+ FC pool water, you should know your pH is in the seven's before you start. When you "come back down" out of the SLAM and below 10 ppm FC, your pH will likely still be in the 7's......right where you want it.
 
For those following at home, I just tested again and my FC was 14.5ppm, down from 22.5ppm at 12:10PM. There's no visual change I can see yet, but the fact that the chlorine seems to be getting used now makes me hopeful. I also verified my CYA level was at 50. This time I'd have called it closer to 40, but due to the subjectiveness(?) of the test, I'd rather error on the high side just to be safe. My plan is to check it again in about 4 hours, brush, and then add whatever bleach is required. Hopefully soon I'll start seeing a color change. That pea green is really, really ugly. I toyed with the idea of adding some DE to the filter to help speed things up, but I have a feeling it might clog too quickly and impede flow. I've used it before to help polish the water, but this is WAY past needing polished.
 
Thanks Felipe! I did backwash the filter yesterday just to be safe. There was no noticeable jump in pressure, but my pressure dial is pretty crappy and I don't put much faith in it. I added some DE to the sand filter this morning, so I'll have to do another backwash in a few hours. The pool is still very green but it's definitely showing signs of improvement. Hopefully the DE will help speed the process up a bit.
 
I've seen some great progress today! My pool is back to a shade of blue now, so I'm super happy. I've been running DE in the sand filter to help things out, leaving it in for around 3-4 hours, backwashing, and then re-adding the DE. I've done this cycle I think 4 times today. I've kept the FC up around 22, having added a total of about 3 128oz 6% bottles throughout the day. I'm planning on continuing on with this routine till I finish the SLAM.

Sorry about the imgur link, when I try to embed a pic it says I'm over my quota, whatever that means...

Imgur: The most awesome images on the Internet
 
Thanks, the pool is now crystal clear! I could've done the OCLT yesterday but decided to just keep the FC at slam level another day to make sure. I'm doing the test tonight and expect it'll pass, so hopefully my slam is complete. It's nice to have the beautiful water again and know my levels are where they need to be. I'll take a pic of the pool in the morning as the "after" picture for this process.
 
That's so great to hear! Yes! Look forward to test results and picture! Your imgur link worked and it was totally fine. If you found TFP helpful, and would like to show your thanks, you can check out the "Support TFP" link at the top. One of the perks of certain donations are increased attachment space, like 10MB-20MB, so you can easily upload big pictures here without things like imgur. While not official TFP policy, I kept all three of my SLAMS that I've done going an extra two days after I passed all three criteria and kept up the brushing, cleaning the filter/backwashing after the first extra day. I also put all my pool hoses, brushes, poles, toys, and vac heads in the pool from sunset until bedtime, maybe 3-4 hours. I don't know if it actually did anything other than make me feel better, but it worked for me.
 
Thanks, and that's a great idea about putting all the equipment in the pool to sanitize it. I think I might follow your lead and do the same! I passed all 3 tests and my SLAM is officially a success, but I may carry the FC levels a little high for a few days just to be safe. After this I'm going to need to replenish my TF-100 test kit, so perhaps a donation would be in order. I've definitely gained more than a few dollars worth of info here! Below is a pic of the pool this morning, but unfortunately it's quite windy so the pic doesn't do justice to the amazing clarity of the water. Thanks again for all the help!

Imgur: The most awesome images on the Internet
 

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