SLAM - not helping my chlorine demand

[ReefGrief]

Hi all,

I was recently told by my pool store that I have a high Chlorine Demand, and they recommended spending hundreds of dollars on burn out. I had already done some research on your site and I knew I had to switch to TFP methods. So, to lower my CYA of 140, I did a partial drain. Here were my readings before I started the SLAM.
FC - .4
CC - 1.0
PH - 7.8
TA - 160
CYA - 60
My water has been crystal blue all along.
I knew I had to get my PH and TA down, so I added 2L of Muriatic Acid, then aerated and my PH came up to 7.2, and my TA was 140. I then started adding bleach. This started on Sep 4. I tested using my T2006 at least 4-5 times per day, and made additions to get it up to SLAM level. This has been going on for 4 days now, and I have gone through 50L of 10.8% chlorinating liquid and still can't pass the overnight test. My FC drops by a range of 5-8.5ppm overnight. This morning when I tested before the sun hit the pool I was at 14.0FC and .5CC. Last night when I tested before going to bed the FC was 22.5. My water is crystal blue, and there is no debris in the pool. I have used my Dolphin to vacuum the pool daily and have sprayed the Dolphins filters and my cartridge filter too. I don't know if I should continue - as the pool will be shut down for the winter in a week or so, and I feel like the SLAM isn't helping my chlorine demand. Do I keep going or is there something else I should be trying?

 

[mknauss]

Welcome to the forum!

This is the time we call POP - or Pool Owner Patience. It takes time to finish the SLAM. Be sure you are testing and dosing with chlorine several times each day.

From others on the forum in cold country they wait until their pool water is consistently at or below 60F (15C) prior to closing. At that temperature algae is inhibited from flourishing.

I would suggest finishing the SLAM now as you will have a much better chance of having clear water in the spring (opening should occur prior to the water being consistently above 60F).

Take care.

 

[splashpad]

Hi all,

I was recently told by my pool store that I have a high Chlorine Demand, and they recommended spending hundreds of dollars on burn out. I had already done some research on your site and I knew I had to switch to TFP methods. So, to lower my CYA of 140, I did a partial drain. Here were my readings before I started the SLAM.
FC - .4
CC - 1.0
PH - 7.8
TA - 160
CYA - 60
My water has been crystal blue all along.
I knew I had to get my PH and TA down, so I added 2L of Muriatic Acid, then aerated and my PH came up to 7.2, and my TA was 140. I then started adding bleach. This started on Sep 4. I tested using my T2006 at least 4-5 times per day, and made additions to get it up to SLAM level. This has been going on for 4 days now, and I have gone through 50L of 10.8% chlorinating liquid and still can't pass the overnight test. My FC drops by a range of 5-8.5ppm overnight. This morning when I tested before the sun hit the pool I was at 14.0FC and .5CC. Last night when I tested before going to bed the FC was 22.5. My water is crystal blue, and there is no debris in the pool. I have used my Dolphin to vacuum the pool daily and have sprayed the Dolphins filters and my cartridge filter too. I don't know if I should continue - as the pool will be shut down for the winter in a week or so, and I feel like the SLAM isn't helping my chlorine demand. Do I keep going or is there something else I should be trying?

Do you have any lights, ladders, ledges/edges where algae could hide? Try brushing around anything that isn't a flat surface

[FC/CYA][/FC/CYA] Your SLAM FC target is 24 with CYA of 60

 

[ReefGrief]

Ok, so day 6 of the SLAM, and the results seem to be getting worse and worse. Last nights OCL was 9ppm (26 to 17). There is no visible signs of any problem with the water. I checked our light and don't see any algae whatsoever, in fact the water has always been crystal clear and there is no debris of any kind anywhere in the pool. What gives? The picture in my avatar was taken yesterday and you can see the water is looking great. So, I have no idea why so much chlorine is being consumed. I am getting frustrated as I am spending $6.99 per 5L jug of 10.8% which is the cheapest option I can find in my area. I am going through about 15L per day so this is adding up. I need reassurance that this will end! Is there something else I should be doing? Here was last nights test results:
FC 26
CC 0.5 ( might be lower as I only get a very slight tinge of pink when I test for this)
PH 7.6
TA 150
CH 360
CYA 60

 

[Donldson]

To lose that much FC overnight there has to be something in the water, no question. Did you add any other chemicals from the pool store in the previous month or so? Anything at all?

 

[duraleigh]

Never lose the basic ideas of TFP.

Chlorine is consumed in your pool by either organics or UV from the Sun. You have CYA protection from the sun's UV to minimize that loss (to about 2 ppm daily).

That unequivocally means the rest of your FC loss is coming from organics in your pool......period.

How do you stop that loss? More chlorine.

Brushing, cleaning your filter and vacuuming are all very important but chlorine will clear your pool.

Of course, you could go to the pool store and purchase "magic" ingredients. They will cost you more and be no more effective.

Stay the course.....follow the SLAM procedures as outlined and your chlorine usage will drop once the organics are consumed.

 

[ping]

Has the filter pressure increased any? You might want to take it apart and give it a good cleaning.

How long has the pool's chlorine demand been high?

 

[PAGirl]

What have you put in the pool prior to the SLAM? Any of the pool store's products? (Taking into account anything a few weeks before) We are finding some stores are using things with bromine, etc. that can really mess with the chemistry.

* oops, just saw someone else already asked this.....

 

[ReefGrief]

What have you put in the pool prior to the SLAM? Any of the pool store's products? (Taking into account anything a few weeks before) We are finding some stores are using things with bromine, etc. that can really mess with the chemistry.

* oops, just saw someone else already asked this.....

i just started the TFP methods of using liquid chlorine in September. Prior to that I was using Bioguard products (burn out, smart shock, smart sticks). The last week of August I used Lithium hypo to chlorinate as I was told my CYA was high and they said that Lithium has no cya in it. That is it. Do you think that stuff is affecting my numbers still? I did do a partial drain before switching to straight liquid chlorine.

 

[ReefGrief]

Has the filter pressure increased any? You might want to take it apart and give it a good cleaning.

How long has the pool's chlorine demand been high?

the filter pressure remains steady at 10. I did spray it off 2 days ago but the pressure didn't change.

The chlorine demand has been high probably since July. We have had a very hot dry summer and had unusual amounts of caterpillars that I kept scooping out of the pool. The caterpillars have been gone since August though.

One thing ink that I didn't mention, is that when my pool was built last June, they plumbed the filter wrong so the water was not being forced through the filter. That resulted in a cloudy pool from day one. They finally realized the problem in June this year and replumbed it. Within 12 hours the pool was crystal clear. Not sure if the water is still playing catch up from this?

 

[splashpad]

i just started the TFP methods of using liquid chlorine in September. Prior to that I was using Bioguard products (burn out, smart shock, smart sticks).

Both the smart shock & smart sticks are stabilized chlorine (adding CYA)

The last week of August I used Lithium hypo to chlorinate as I was told my CYA was high and they said that Lithium has no cya in it. That is it. Do you think that stuff is affecting my numbers still? I did do a partial drain before switching to straight liquid chlorine.

Is the CYA 60 from your personal dot test or the pool store test?

- - - Updated - - -

the filter pressure remains steady at 10. I did spray it off 2 days ago but the pressure didn't change.
The chlorine demand has been high probably since July. We have had a very hot dry summer and had unusual amounts of caterpillars that I kept scooping out of the pool. The caterpillars have been gone since August though.

How much of the stabilized chlorine did they have you adding? (thankfully the plumbing issue was corrected before the caterpillar invasion!)

Who said there was a high chlorine demand? (How long have you tested your pool water yourself?) Sorry if I missed that info!

 

[ping]

Liquid chlorine and following the SLAM procedure is the answer. There was a lot of stuff that was brewing for a long time that never had enough FC to get rid of it.

You might want to do another 50% water change to lower the CYA even more. It is much easier to SLAM at 30 CYA than 60 and it will take less chlorine to get the job done.

 

[Tomolena]

Maybe a non-sequitor, but 2 liters of Muriatic acid seems like an awful lot for a pool that size. pH Wasn't even out of range at that point.

 

[ReefGrief]

Both the smart shock & smart sticks are stabilized chlorine (adding CYA)


Is the CYA 60 from your personal dot test or the pool store test?

- - - Updated - - -


How much of the stabilized chlorine did they have you adding? (thankfully the plumbing issue was corrected before the caterpillar invasion!)

Who said there was a high chlorine demand? (How long have you tested your pool water yourself?) Sorry if I missed that info!

the cya was tested using my own dot test.

I was adding 2 pucks every 3 days or so, shocking with burnout weekly and still not able to hold a FC of 1-3.

I have been been testing myself since the beginning of September when my Taylor k2006 arrived.

- - - Updated - - -

Maybe a non-sequitor, but 2 liters of Muriatic acid seems like an awful lot for a pool that size. pH Wasn't even out of range at that point.

No, you are right, but I thought I read in Pool School that I should adjust all my parameters prior to starting the slam, and I was using the acid to lower TA. I then aerated to bring PH back up. Not sure if that was the right thing to do?

- - - Updated - - -

Liquid chlorine and following the SLAM procedure is the answer. There was a lot of stuff that was brewing for a long time that never had enough FC to get rid of it.

You might want to do another 50% water change to lower the CYA even more. It is much easier to SLAM at 30 CYA than 60 and it will take less chlorine to get the job done.

Yes, and I would do that if it were the beginning of the swimming season, but I will be closing down the pool in the next couple weeks. Our temp is on average 12 degrees C by the end of September so I will be draining to below the returns and winterizing soon. I'm wondering if it was a bad idea to try to fix the chlorine demand so close to the end of the season?

 

[mknauss]

It actually should be easier to defeat the algae that is consuming your FC when the water is cool.

Only parameter that needs to be adjusted, typically, is pH prior to a SLAM.

Did you do a lot of water draining when using the tabs? I would think your CYA would be much higher if your pool got a steady diet of them before.

Take care.

 

[ReefGrief]

Yes, it was much higher prior to draining (140) but that number was from a pool store test so who can be sure? I tested after the drain, using my own test, and it is now 60. I hope that my close out drain brings it down further and I open next year with a cya of 30 ish.

 

[splashpad]

No, you are right, but I thought I read in Pool School that I should adjust all my parameters prior to starting the slam, and I was using the acid to lower TA. I then aerated to bring PH back up. Not sure if that was the right thing to do?

Yes you are correct, because most of the test results are null/invalid with chlorine levels over 10ppm

Yes, and I would do that if it were the beginning of the swimming season, but I will be closing down the pool in the next couple weeks. Our temp is on average 12 degrees C by the end of September so I will be draining to below the returns and winterizing soon. I'm wondering if it was a bad idea to try to fix the chlorine demand so close to the end of the season?

Yes it would be better to have it "stable" and "clean" upon closing, otherwise you could open to a green pool (unless you open before 60F/15C) and address it then. It will have to be addressed, just a question of when more so =)

It sounds like you are on the tail-end of the SLAM, just a little more patience & persistence on your part!

 

[ReefGrief]

Ok then! I will try to have more patience. I appreciate all the advice! I have decided to pressure wash my foam blanket cover as well because I can't imagine where all the organic material is coming from....might be a dirty cover?

 

[Oly]

....might be a dirty cover?

Yes anything in contact with your pool water must be cleaned including mats, fill pipes, ladder, light fixture, skimmer, hoses, pool tools, toys, etc.

Pressure washing alone is not enough you need to sanitize.

 

[duraleigh]

Yes you are correct, because most of the test results are null/invalid with chlorine levels over 10ppm

No, that only applies to the pH test.