Do you SLAM after a lot of rain water?

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CoolHome

CoolHome

Well-known member
Jun 6, 2020
72
Crawfordsville, IN
Pool Size
6000
Surface
Vinyl
Chlorine
Liquid Chlorine
When we filled our pool (Coleman metal-frame 18'x48") we only filled it about 3ft deep (around 5700 gallons) to start with. I didn't want it too full for my youngest. We've had a ton of rain in the last few days and I calculate we've added nearly 500 new gallons of rainwater and it's still coming down. This is good in some ways because we filled from the well and I'm struggling with high iron and high TA (250 last time I tested) so rainwater is welcome and there is room in the pool. However, we were just gone on a trip and I had someone adding a maintenance amount of chlorine, but our PH got high, over 8ppm and the water got cloudy. I've ordered more metal sequestrant, was letting the chlorine fall so I could add it Monday, and meanwhile am trying to filter out as much of the iron as I can while I wait for it to arrive. Now I'm wondering if I'm going to have to SLAM because of the new water? If so it will oxidize the iron in the water and turn it brown, and I'll have to leave it like that while waiting for the chlorine to go down enough to add the sequestrant, plus my PH is still high. What order do I do this all in?
 
The cloudiness is not from the iron, it's probably algae in its early stages. Can you post a full set of water test results? That would be the best place for us to start. Don't bother adding any sequestrant until you know for sure there is no algae, otherwise the chlorine will just eliminate the sequestrant. Always treat for algae first, then staining if present. Take full advantage of that rainwater. The less well water the better.
 
Well, I'd kind of thought algae was unlikely just because when I got back Weds night FC was 3, I added chlorine that night and got it up to 5ppm by the Thursday morning, and it only went down to 4ppm by Friday morning and that was with a super hot sunny Thursday. I did just get a break in the rain though so here are my numbers today using the Taylor K-2006 Complete kit:

FC - 2*
CC - 0
PH - 7.9
TA - 250
CH - 250
CYA - 55 (which is surprising because it was 50 before I left and I haven't added more, but maybe the water's general cloudiness is affecting it?)

*I would have expected FC to be 3 because I didn't add Chlorine this am but it's just been diluted by 3-4" of fresh rainwater since last night and yesterday was super sunny and my kids were in the pool for several hours, so this doesn't seem like a high loss to me, but I'm still new at this.

Below is my progression since I got back from my 5-day trip Weds night.

Day: Weds pm - Thurs am - Fri am - Sat mid-day
FC: 3 - 5 - 4 - 2. (added chlorine Weds pm and not since)
CC: .5 - 0 - 0 - 0
PH: 8+ - 8 - 7.7 - 7.9. (added muriatic acid Weds pm/Thurs am/Thurs pm)
TA: didn't test - 250 - (didn't test) - 250
CH: didn't test - 175* - (didn't test) - 250
CYA: didn't test - 65* - didn't test - 55

Notes: Chlorine and MA were added based on the Pool Math calculator but the PH didn't want to budge and I only got it down to 7.7 and its up again already. I've had some confusion with the Calcium Hardness test, I'm pretty sure I stopped when it turned purple on Thursday which is why it shows as lower. Today it turned purple at 6 drops but I kept going to see if it would turn an actual blue which it did at 10 drops. I was using a 10ml sample so 10x25=250. I really am confused by the CYA test, but this is another one I struggle with, it had been consistently at 50 before I left and I came back to it testing at 65 and nothing but liquid chlorine would have been added while I was gone, so I'm really wondering if the general cloudiness of the water has affected it. Today with super low light out the dot disappeared to a casual look at about 60 but looking super close I could still see it until 55.
 
I can see the CYA seems tricky for you, so unless you are using pucks (which increase the CYA) it must be a testing thing. But if we were to use the lower CYA you rcroded (50), you can see from the FC/CYA Levelsthat your FC has been much too low. The ideal ranges was 6-8 and never below 4. If we assume a higher CYA, then the FC needed to be much higher. So that is why algae would be a concern.

As for the CYA test, it can be the most difficult for some. Here are my notes:
CYA Testing:
Proper lighting is critical for the CYA test, so you want to test for CYA outside on a bright sunny day. Taylor recommends standing outside with your back to the sun and the view tube in the shade of your body. Use the mixing bottle to combine/gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Then, while holding the skinny tube with the black dot at waist level, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. If it helps, pour a little, look away, then look back and pour some more. Some people like to squirt enough solution to go line-by-line for a better feel. Once it disappears, record the CYA reading. After the first test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate the CYA reading. If you are still questioning your own results, have a friend or two do the same test 2-3 times. Share your results only after everyone is done to see if you came up with the same average results.
Click to expand...
 
Thanks for the CYA testing tips! I've definitely been holding it closer. Its tricky because I need reading glasses for close stuff. Waist level will be a tricky distance. I started with 0 CYA and added stabilizer based on a goal of 40ppm. I have never added more since that original add. Sounds like I should SLAM it to be on the safe side. How do you take care of stains? Should I add sequestrant after the chlorine levels are back to normal then adjust PH?
 
Once you complete the SLAM Process and are sure to pass all 3 SLAM criteria, then you can evaluate any residua iron stains. If there are only a few, you can spot-treat them with Vitamin C tablets in a sock (crushed). If staining is widespread, a complete Ascorbic Acid treatment may be next. But we'll come back to that as an AA treatment can be a bit tricky. During the SLAM, I would recommend placing white towels, cotton t-shirts, or polyfill in your skimmer to collect any iron that may precipitate out of clear solution. The more you filter now the better.
 
Does putting all that in the skimmer affect the pool circulation for mixing the chlorine? I don't have a skimmer proper, there is a plastic screen over the return. I have put 3 socks layered over it before and caught iron that way, though it doesn't seem to move the water much when they are there, so I've worried about circulation and only done it when I'm not adding chemicals. Currently, I have put a Polypropylene 1 Micron bag over the return hose to try and filter out a bit more. Can't say if it's working better than the socks or not. Here is the picture of it and the pool at the moment. I'm going to go down and hook the return hose back up to the jet and add Muriatic Acid to try and get the PH down. I hope I have more luck than I have so far this week! I've added quite a bit of MA already and its barely budged! Is there any reason not to overshoot a bit? Go for 7.0 PH? Maybe I can get it down enough to SLAM tonight before bed.
 

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Texas Splash said:
I can see the CYA seems tricky for you, so unless you are using pucks (which increase the CYA) it must be a testing thing. But if we were to use the lower CYA you rcroded (50), you can see from the FC/CYA Levelsthat your FC has been much too low. The ideal ranges was 6-8 and never below 4. If we assume a higher CYA, then the FC needed to be much higher. So that is why algae would be a concern.

As for the CYA test, it can be the most difficult for some. Here are my notes:
Click to expand...
Added muriatic acid yesterday evening and got PH down to 7.2 by nightfall so I added Chlorine before bed to get to SLAM level of 20ppm. When I measured this morning it was still 19.5, I tested for CC but didn't see a color change until I was pouring it out, so I may have a bit. I'll be testing again in a few hours. I'm wondering about that small loss though? Shouldn't I have lost more if there was the beginning of algae in there? Amazingly the water did not turn brown this time! Maybe between what I've been able to filter out and the extra rainwater the iron content has gone down enough not to oxidize at SLAM level, that would be nice.

Texas Splash, I only had enough reagent for one more CYA test (I've ordered more but it probably won't be here until mid-week) and we do not have a bright, sunny day unfortunately but I thought it was probably important to try and get my CYA measurement right if I was SLAMMING so I used the last of it to test. I did the test a bunch of times and had my husband do it too. He was getting a lower number than me, something he was doing was shading it because there was a lot of light reflection. When I tried that I got a lower number too. He also has actual prescription glasses while I use magnifying readers for close things, waist level is right at that line for me where I can still need them for somethings. I definitely noticed a difference of about 5ppm if I wore my magnifiers or not, I also noticed it really mattered where the light was coming from. For my last attempt, I tried it inside in my brightest room, a bathroom with many bright lights and a window. If the light came in from the side at all it highlighted the dot more. I definitely didn't get a reading higher than 50ppm through and between all our attempts the average was 45 ppm. 40 had been my goal when adding stabilizer originally so I'd like to believe that was right. Something I was also doing before was shaking it pretty vigorously for 30 seconds, rather than gently and rest for 30. So maybe my higher readings before were due in part to extra oxygen clouding the water from the hard shaking. I'll use 50 as my number for CYA for now, I imagine overdoing the chlorine is better than under-doing it while you SLAM.
 
It's good to have a partner do the CYA test with you. But you always want to do it outside with the midday sun at your back or over your shoulder. Indoor lighting is never recommended for the CYA test as it gives a different result. Also, only want to shake the mixing bottle gently. If you shake it too hard or too much, it can skew the testing.
 

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zea3 said:
Here is a link for a DIY iron filter that works for steel frame pools.
or try this
Click to expand...
Thanks zea3. I've seen both those methods though that is by far the best video explaining how to do the bucket method. I'm currently using the sock method as it hasn't required any fancy equipment and I also haven't had my iron oxidize and settle like that. If I ever do I probably will try the bucket method, but I don't want to bring it on if I can help it! Going to go check my FC/CC levels now!
 
Doing a SLAM of my pool, here's my original thread that lead to that if you're interested: Do you SLAM after a lot of rain water?

I'm using the Taylor K-2006 Complete testing kit. So last night, after dark I put in liquid chlorine with a goal of getting FC= 20 ppm. I tested this morning and it was 19.5 ppm. Fine. I just tested now, about 4 hours later and got 21 ppm! I did brush the pool good this morning after that first test. Could that extra mixing account for the higher reading? I didn't add more chlorine. I took my sample from elbow deep, but maybe the chlorine hadn't dispersed good overnight. I don't have the best pump (see signature).

Also, how long do you allow the R-0003 to sit in your sample before you decide there is no CC? This morning I added it to sample and it was clear, I recorded 0 then as I was dumping it I noticed it looked slightly pink. When I tested just now and added the R-0003 it looked like maybe it was slightly pink, I added 1 drop of the R -0871 and it got 100% clear looking so I recorded .5ppm CC. I took it all inside to rinse out and then it was pinker again, so I added a second drop. It cleared, then after a bit it got pink again. So now I'm confused.

I'm thinking now I probably didn't need to SLAM since I've lost no chlorine since I added last night, but the CC reading is throwing me off.

Oh yes, CYA is 50 (I believe). I've had some trouble decoding the test and we haven't had any sun for the last couple days, but that is the number I've gotten most times I've tested, it is not higher than 60. That's the highest I've ever gotten and I only every put in enough stabilizer to get 40 ppm so even if I over estimated my total gallons originally, I doubt I over shot by much.
 
An expert may chime in differently, but the test error + or - is .5 I believe, which could contribute. Poor circulation can also. Are you taking the sample from the same spot each time? Mine varies a little bit, depending on the area I test. I am thinking the 3 potential contributors led to the 1.5 difference.

Once the solution goes clear, the test is done. It is not unusual for it to turn slightly pink after a bit.
 
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Msch99 said:
An expert may chime in differently, but the test error + or - is .5 I believe, which could contribute. Poor circulation can also. Are you taking the sample from the same spot each time? Mine varies a little bit, depending on the area I test. I am thinking the 3 potential contributors led to the 1.5 difference.

Once the solution goes clear, the test is done. It is not unusual for it to turn slightly pink after a bit.
Click to expand...

Awesome Msch99 and Divin Dave! Thank you! This is what I was hoping. Looks like my CC is 0 then.

Msch99 -that makes sense. I take it from the same spot everytime, but I feel like I may have reached down a little deeper this last time.
 
I'm struggling with if I even need to SLAM, my FC levels are NOT falling. I'm running out of reagent for FC and already out of reagent for CYA. I'd ordered more before I even knew I would try to SLAM but they won't be here until towards the end of the week.

So I started SLAM. Saturday evening I dropped my PH to 7.2, then added chlorine to get FC to 20ppm. I was going on my CYA being 50, but I'd struggled to interpret the test. Well it stayed steady at 20 overnight, and only lost 1ppm over the course of the whole day, which was mostly overcast but got sunny at the end. I didn't even add anymore Chlorine before bed because it was still 19ppm when I tested after dark. Test first thing in the morning before the sun had barely peaked over the horizon and had lost 1.5ppm. ARGH. More than the 1 allowed for the OCLT, but within the margin of error too. CC was .5 this morning (or less, it was so faintly pink I almost didn't add a drop) So I decided to SLAM at a higher level in case I've been mistaken about my CYA reading, I'd once got 60 (though most times I tested it was around 50). Put in chlorine to reach 24ppm at 7am this morning. Just tested (7 hours later) and my FC is 24.5 and CC is 0. Its been sunny all day! I've brushed the pool twice. If everytime I test I need 40-48 drops to get a reading I'm going to run out of reagent long before my refill gets here and if my FC isn't going down, even in the bright sunlight why am I doing SLAM? Is there another reason it wouldn't fall? I started with CYA of zero and orginally added stabilizer to try to get it to 40, so I can't imagine its more than 60 in a worse case scenario, my water level went up recently because of rain so it should dilute the CYA.

Recap:
Last night reading:
FC -19
CC - .5
PH - 7.0 (lowered it from 7.2 about 1/2 hour before adding chlorine)
TA - Didn't test
*Didn't add chlorine

This morning 6:30am:
FC - 17.5
CC - .5
PH - 7.1 (used my husband's hydroponic PH meter not the reagent for a quick check this am, they are usually in accord or very close)
TA - didn't test
*Added 54oz chlorine at 7am to get to 24ppm
*Brushed good after about 1/2 hour

This afternoon 2:30pm:
FC - 24.5
CC - 0
PH - 7.0 (Husband"s PH meter says 7.2)
TA - 200 (this is down from 250 since Saturday - yay for that!)
*Brushed good about a 1/2 hour or so before this test.

What to do? Keep on, even though I'll likely run out of reagent? I maybe have 5 tests left and the new reagent is due Friday, CYA reagent should be here Weds. Maybe I should let it fall to zero and add Metal Out and see what happens then and start SLAM again if that doesn't fix it?
 
Last edited:
duraleigh said:
Testing error either on one test or the other or both. Chlorine can ONLY go up if you add chlorine to your pool.
Click to expand...

HELP! I just don't know what to do...

Just tested at 8:45pm, over 6 hours since last test, bright sunny day.
FC - 24
CC - .5
PH - 7.0 (this is what the color test is saying, meter is still saying 7.2, either way hasn't changed)

FC only went down .5 over the course of the whole day!

Should I just wait and see how much it goes down tonight? Raise the chlorine to a SLAM level of 28 and see what happens? That's my last thought in case my CYA is actually higher than even 60, but I'm 100% certain I couldn't have a CYA level of more than 70 (no matter how hard its been to be sure I'm truly no longer seeing the dot in the CYA test I've always seen the dot clearly at 70) and that still seems highly unlikely to me. The filter has been going 24/7, I'm putting in a clean cartridge morning and night. I put in a brand new cartridge this morning and there was nothing in it but bugs this evening. I'm brushing and skimming the pool several times a day. I don't have a vacuum yet (I ordered one last week and am still waiting) and I'm sure there are at least some leaves and stuff on the bottom (my teenage helper said she was skimming for bugs and leaves, but we did have lots of storms) but I'm not sure how bad because I can't see the bottom! I get a few come up when I brush and and I grab them with the net. I get a bit of that pure bleach smell when I'm right over the pool water, but I don't get that "chlorine" smell I usually associate with pools. Doesn't that mean the chlorine isn't "eating" anything? Maybe I don't have an algae problem? I'm still just wondering if that fact that my PH shot up while I was gone isn't the main reason for the cloudiness. Need some guidance, I'm flying blind.
 

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