SLAM Process - Chlorine Staying High

[Rhollerud]

Help! Second year with our pool. Last August the pool turned green and we haven’t been able to get it cleared up. We just got our Taylor test kit and started the SLAM process on Monday night. I have attached a photo of our tests since then.

Obviously we are only a few days in, but chlorine is staying really high. Our home test showed 18.2 FC the morning after we added chlorine, and then 17.5 by the end of that day - not much was consumed. We added another gallon last night for good measure. This morning we tested 22.5 FC at home and were baffled at how high it was so we went and got pool store testing which said it was 14.42. When my husband got back home he retested that same water and it was 17.

Couple questions:
-How do we know our results are accurate? We follow instructions and have watched videos on the testing.
-Why wouldn’t the chlorine drop more on day 1? I’ve heard about people having to add chlorine every few hours to keep it at SLAM levels. How do we know the process is working? The water color hasn’t changed at all. Still green. We vacuumed last night and don’t feel like it did much.

Other info:
-Over the weekend we drained the pool to 1/3 to get CYA down, which it did. We refilled with our well water filtered through an RV filter.
-We had our equipment inspected last year and all checked out. We replaced sand, too.
-We have tried adding Metal Out and floccing the pool with no success. Also lots of backwashing, vacuuming, running pump 24/7, etc.
-We had the store test for phosphate, which was through the roof. But have seen advice that that doesn’t matter as long as you have enough chlorine. Posted those full results, as well.

Any thoughts on our next steps? I feel like we’ve been trying everything.

 

[FlappyLipps]

It can take weeks to finish the SLAM process.

The taylor kit is correct the pool store is wrong.

floccing = clogged pool filter

Metal Out and phosphate, pool store words to sell you more of xxxx chemicals you don't need.

 

[Bperry]

Help! Second year with our pool. Last August the pool turned green and we haven’t been able to get it cleared up. We just got our Taylor test kit and started the SLAM process on Monday night. I have attached a photo of our tests since then.

Obviously we are only a few days in, but chlorine is staying really high. Our home test showed 18.2 FC the morning after we added chlorine, and then 17.5 by the end of that day - not much was consumed. We added another gallon last night for good measure. This morning we tested 22.5 FC at home and were baffled at how high it was so we went and got pool store testing which said it was 14.42. When my husband got back home he retested that same water and it was 17.

Couple questions:
-How do we know our results are accurate? We follow instructions and have watched videos on the testing.
-Why wouldn’t the chlorine drop more on day 1? I’ve heard about people having to add chlorine every few hours to keep it at SLAM levels. How do we know the process is working? The water color hasn’t changed at all. Still green. We vacuumed last night and don’t feel like it did much.

Other info:
-Over the weekend we drained the pool to 1/3 to get CYA down, which it did. We refilled with our well water filtered through an RV filter.
-We had our equipment inspected last year and all checked out. We replaced sand, too.
-We have tried adding Metal Out and floccing the pool with no success. Also lots of backwashing, vacuuming, running pump 24/7, etc.
-We had the store test for phosphate, which was through the roof. But have seen advice that that doesn’t matter as long as you have enough chlorine. Posted those full results, as well.

Any thoughts on our next steps? I feel like we’ve been trying everything.

Your high CC level is indicative of something consuming chlorine so it’s working. That’s pretty bad looking water.

Switch your chlorine testing to use the 10ml sample and then each drop of reagent = 0.5ppm FC. No need for the extra accuracy on that and it’ll save you reagent.

 

[Rhollerud]

Your high CC level is indicative of something consuming chlorine so it’s working. That’s pretty bad looking water.

Switch your chlorine testing to use the 10ml sample and then each drop of reagent = 0.5ppm FC. No need for the extra accuracy on that and it’ll save you reagent.

We learned that right away and started using the lower amount. I was hoping that means it’s working! Because you definitely can’t tell by looking at it. We just deep cleaned the sand, so I hope that helps because it didn’t feel like it was filtering very well.

 

[Bperry]

We learned that right away and started using the lower amount. I was hoping that means it’s working! Because you definitely can’t tell by looking at it. We just deep cleaned the sand, so I hope that helps because it didn’t feel like it was filtering very well.

Stay away from the floc and clarifier in the future as they can cause more problems than they solve. Even if used exactly as prescribed they can be messy. You just need chlorine, filtering, and time.

 

[tikoh]

Have you tested CYA yourself?

 

[Rhollerud]

Stay away from the floc and clarifier in the future as they can cause more problems than they solve if. Or used exactly as prescribed, even then they can be messy. You just need chlorine, filtering, and time.

It’s the time (and energy) that’s running out!

Have you tested CYA yourself?

Yes, we have. It was 37 when we started.

 

[Drd]

Aglae! be aggressive, for yellow I skim, clean all baskets, Brush, Brush, Brush (it breaks the algae shell and opens it up to the chlorine), slam/shock- ad 2 gals of HASA 15 ppm chlorine I get from a pool store, filter, next day same thing with 1 gal usually clears. Also clean your tools and anything else like floats in a chlorine bath or wipe them down too. Green, you need to get it out right away as it will turn into black and bore itself into your plaster and stain even if you get rid of it then you have to acid wash it to get it clean again and you still might have some gray spots left. As it gets warmer outside and heats up the pool, conditions for algae to grow increase if it has a food source like bacteria from stuff that gets into your pool and chlorine levels are not sufficient. Checking your chlorine levels daily when it gets warmer/hot out is important also CYA and PH at recommended levels all play apart.

 

[JJ_Tex]

It’s the time (and energy) that’s running out!

Yes, we have. It was 37 when we started.

Lets reset expectations on the timing. A SLAM is a process that generally takes a week or more, and based on your pictures likely more. It looks like you are only on day 3. If needed, take a picture each day so you can see the progress and hopefully ease the frustration, but you have a ways to go. Keep in mind that it didn't get this way overnight and is not going to be cleared up overnight.

The other thing I notice is your CYA fluctuations. Unless you are adding CYA or draining water, test it once and only focus on the FC for now. Even the CC is unnecessary at this point. Your CYA numbers range from 35 to 43 over the last few days. Please confirm that is with your own test kit (which should be even numbers only). If you are comfortable with the numbers on your spreadsheet, take 43, round up to 50 and call that your CYA which means your SLAM FC is 20. Keep it at 20 until you pass all 3 SLAM tests (clarity, CC <1, OCLT) which will be in at least a week.

 

[Rhollerud]

Lets reset expectations on the timing. A SLAM is a process that generally takes a week or more, and based on your pictures likely more. It looks like you are only on day 3. If needed, take a picture each day so you can see the progress and hopefully ease the frustration, but you have a ways to go. Keep in mind that it didn't get this way overnight and is not going to be cleared up overnight.

The other thing I notice is your CYA fluctuations. Unless you are adding CYA or draining water, test it once and only focus on the FC for now. Even the CC is unnecessary at this point. Your CYA numbers range from 35 to 43 over the last few days. Please confirm that is with your own test kit (which should be even numbers only). If you are comfortable with the numbers on your spreadsheet, take 43, round up to 50 and call that your CYA which means your SLAM FC is 20. Keep it at 20 until you pass all 3 SLAM tests (clarity, CC <1, OCLT) which will be in at least a week.

I haven’t been really focusing on CYA, just taking to show others that may ask. Yes it’s with a home test, why wouldn’t the numbers be odd if they are in between lines?

So, I have been using 17 as my bottom line since that’s what the pool math calculator said. I know it’s a process but do you have an explanation why a green pool with this much algae wouldn’t be breaking down the chlorine faster?

We deep cleaned our sand filter yesterday which looked disgusting so hopefully that helps start to process out some of the algae.

 

[Rhollerud]

Lets reset expectations on the timing. A SLAM is a process that generally takes a week or more, and based on your pictures likely more. It looks like you are only on day 3. If needed, take a picture each day so you can see the progress and hopefully ease the frustration, but you have a ways to go. Keep in mind that it didn't get this way overnight and is not going to be cleared up overnight.

The other thing I notice is your CYA fluctuations. Unless you are adding CYA or draining water, test it once and only focus on the FC for now. Even the CC is unnecessary at this point. Your CYA numbers range from 35 to 43 over the last few days. Please confirm that is with your own test kit (which should be even numbers only). If you are comfortable with the numbers on your spreadsheet, take 43, round up to 50 and call that your CYA which means your SLAM FC is 20. Keep it at 20 until you pass all 3 SLAM tests (clarity, CC <1, OCLT) which will be in at least a week.

Also we have been at it for longer than 3 days (try 2+ months), so that’s where the exhaustion comes from. My husband has already given up so I’m the last chance to save it! It’s too bad we didn’t discover this site sooner.

 

[Mdragger88]

I haven’t been really focusing on CYA, just taking to show others that may ask. Yes it’s with a home test, why wouldn’t the numbers be odd if they are in between lines?

You can’t read the turbidity test between the lines as it is not logarithmic (notice that the lines are not the same distance apart) so if the dot dissapears between two lines always round up ie. Between 40& 50= 50.

So, I have been using 17 as my bottom line since that’s what the pool math calculator said. I know it’s a process but do you have an explanation why a green pool with this much algae wouldn’t be breaking down the chlorine faster?

at the beginning it usually is pretty quick fc consumption but things can vary so just keep at it.
For the fc & cc tests use a 10ml sample & each drop counts as .5ppm
This will not only conserve reagents but will make testing errors less likely as there will be fewer drops to count.

We deep cleaned our sand filter yesterday which looked disgusting so hopefully that helps start to process out some of the algae.

Great hopefully the floc didn’t wreak too much havoc on your sand.
Your iron level is borderline - ideally you want zero metals. Are you on a well?
As you get going with the slam and things start to clear up, if the green remains you may try adding some polyfill in the skimmer to catch any iron but the algae must be dealt with first & foremost.
Keep with the
SLAM Process
For a successful SLAM Process
you need to continue to MAINTAIN Slam level fc for your cya as often as possible (multiple times per day is best) until you meet ALL 3 end of slam criteria-

You are done when:

CC is 0.5 or lower;
You pass an Overnight Chlorine Loss Test
AND
the water is clear.
(Crystal Clear w/no algae dead or alive)

*Check & scrub every nook & cranny where algae may hide (light niches, steps, drain covers, ladder handrails, skimmer throats/weirs, abandoned lines, autofill, overflow drains, etc.)
*If water can go there, algae can thrive there.
*Run slam level water through all water features & lines for at least a couple hours a day during the SLAM Process.
*Brush & or vac daily (this breaks up biofilms that algae uses to protect itself from chlorine)
*Backwash/clean filter when pressure rises 25%over clean pressure.

 

[MITBeta]

slam/shock- ad 2 gals of HASA 15 ppm chlorine I get from a pool store, filter, next day same thing with 1 gal usually clears.

This is the "dump and pray" method. At TFP we promote the SLAM Process method using empiral tools (Test Kits Compared) to guide it.

 

[Rhollerud]

You can’t read the turbidity test between the lines as it is not logarithmic (notice that the lines are not the same distance apart) so if the dot dissapears between two lines always round up ie. Between 40& 50= 50.

at the beginning it usually is pretty quick fc consumption but things can vary so just keep at it.
For the fc & cc tests use a 10ml sample & each drop counts as .5ppm
This will not only conserve reagents but will make testing errors less likely as there will be fewer drops to count.

Great hopefully the floc didn’t wreak too much havoc on your sand.
Your iron level is borderline - ideally you want zero metals. Are you on a well?
As you get going with the slam and things start to clear up, if the green remains you may try adding some polyfill in the skimmer to catch any iron but the algae must be dealt with first & foremost.
Keep with the
SLAM Process
For a successful SLAM Process
you need to continue to MAINTAIN Slam level fc for your cya as often as possible (multiple times per day is best) until you meet ALL 3 end of slam criteria-

You are done when:

CC is 0.5 or lower;
You pass an Overnight Chlorine Loss Test
AND
the water is clear.
(Crystal Clear w/no algae dead or alive)

*Check & scrub every nook & cranny where algae may hide (light niches, steps, drain covers, ladder handrails, skimmer throats/weirs, abandoned lines, autofill, overflow drains, etc.)
*If water can go there, algae can thrive there.
*Run slam level water through all water features & lines for at least a couple hours a day during the SLAM Process.
*Brush & or vac daily (this breaks up biofilms that algae uses to protect itself from chlorine)
*Backwash/clean filter when pressure rises 25%over clean pressure.

Yes we have well water. We thought maybe the iron was part of the problem last year but I’m not so sure. I’ve read about the bucket trick and definitely want to give that a try for stubborn particles.

 

[Rhollerud]

You can’t read the turbidity test between the lines as it is not logarithmic (notice that the lines are not the same distance apart) so if the dot dissapears between two lines always round up ie. Between 40& 50= 50.

at the beginning it usually is pretty quick fc consumption but things can vary so just keep at it.
For the fc & cc tests use a 10ml sample & each drop counts as .5ppm
This will not only conserve reagents but will make testing errors less likely as there will be fewer drops to count.

Great hopefully the floc didn’t wreak too much havoc on your sand.
Your iron level is borderline - ideally you want zero metals. Are you on a well?
As you get going with the slam and things start to clear up, if the green remains you may try adding some polyfill in the skimmer to catch any iron but the algae must be dealt with first & foremost.
Keep with the
SLAM Process
For a successful SLAM Process
you need to continue to MAINTAIN Slam level fc for your cya as often as possible (multiple times per day is best) until you meet ALL 3 end of slam criteria-

You are done when:

CC is 0.5 or lower;
You pass an Overnight Chlorine Loss Test
AND
the water is clear.
(Crystal Clear w/no algae dead or alive)

*Check & scrub every nook & cranny where algae may hide (light niches, steps, drain covers, ladder handrails, skimmer throats/weirs, abandoned lines, autofill, overflow drains, etc.)
*If water can go there, algae can thrive there.
*Run slam level water through all water features & lines for at least a couple hours a day during the SLAM Process.
*Brush & or vac daily (this breaks up biofilms that algae uses to protect itself from chlorine)
*Backwash/clean filter when pressure rises 25%over clean pressure.

My husband just informed me that our filter pressure has never been above 14, except for tonight after we added some DE it got up to 16. Is that normal? It does go down to zero when pump is turned off. We’ve been feeling like it hasn’t been working.

 

[Mdragger88]

My husband just informed me that our filter pressure has never been above 14, except for tonight after we added some DE it got up to 16. Is that normal? It does go down to zero when pump is turned off. We’ve been feeling like it hasn’t been working.

What is your clean pressure after backwashing?

 

[Rhollerud]

What is your clean pressure after backwashing?

14 I believe. It doesn’t change much.

 

[Mdragger88]

14 I believe. It doesn’t change much.

A new gauge is cheap. I like the glycerin filled ones from tftestkits. I also remove the gauge for winter to prevent damage.

Center-mounted Pressure Gauge

tftestkits.net

Also, Are you backwashing frequently? Sand filters actually work better when they are a little bit dirty. That’s kinda what the de does- dirty it up a bit so it grabs more stuff.
Try waiting to backwash until pressure rises 25% over clean pressure which would be about 17.5 psi for you if clean is 14. Unless flow slows before then.
Then when you do backwash do it thoroughly until the water in the sight glass is clear & stays that way (there may be some sand). This should take several minutes. Then rinse until the sand is gone from the sight glass. At least a minute or two .
If your sight glass is dirty clean it so you can see what’s going on well. When the mpv is set to filter & the pump is off you should be able to unscrew the sight glass without water going everywhere.

 

[Rhollerud]

A new gauge is cheap. I like the glycerin filled ones from tftestkits. I also remove the gauge for winter to prevent damage.

Center-mounted Pressure Gauge

tftestkits.net

Also, Are you backwashing frequently? Sand filters actually work better when they are a little bit dirty. That’s kinda what the de does- dirty it up a bit so it grabs more stuff.
Try waiting to backwash until pressure rises 25% over clean pressure which would be about 17.5 psi for you if clean is 14. Unless flow slows before then.
Then when you do backwash do it thoroughly until the water in the sight glass is clear & stays that way (there may be some sand). This should take several minutes. Then rinse until the sand is gone from the sight glass. At least a minute or two .
If your sight glass is dirty clean it so you can see what’s going on well. When the mpv is set to filter & the pump is off you should be able to unscrew the sight glass without water going everywhere.

We may look into a new gauge or even a new filter entirely. I’m not sure if it was the DE but it's visibly less cloudy! We have tried both - backwashing once per day, and backwashing once per week or less (so many differing opinions), and the result was really the same. It's an old pool and so I'm sure the equipment is old. We wanted to get a couple summers of use to see if we even wanted to keep the pool before spending money on new equipment. We've already spent thousands on useless chemicals. Excited we are figuring it out.

 

[Mdragger88]

We’re excited for you! It will be
How Clear is TFP Clear? soon!
The 25% thing is just a good rule of thumb.
For reference my pool is a little bigger than yours & has the same size filter. Without any algae incidents I only backwash a handful of times during the 7 months my pool is open. I have only had the flow slow once in 5 years and it was yesterday after I had added a bit more de after a party & it had quickly risen beyond 25%.
Otherwise I stick to the 25% thing pretty easily. I usually always add 1 cup of de after backwashing.