SLAMing for 2 weeks!

[727Pool_Life]

See my first thread here: https://www.troublefreepool.com/threads/164218-Problems-after-Heat-Pump-Install

I have been SLAMing for 2 weeks now, 3 days of it at mustard algae levels (went as high as 57ppm, just to be safe) and I still cannot pass the OCLT..... water is crystal clear and CC is 0.0.

I feel like I have been more than patient....... What else can I possible do?!?!

 

[YippeeSkippy]

How much FC are you losing each night? How high are you taking it and what is your CYA level?

Maddie

 

[Poolzzz]

Reading the thread it seems you've covered your bases assuming you've searched everywhere for hidden algae.

What fc level have you been doing your oclt at? Seems its up around 40ppm which is too high for a meaningful test. For a cya=50 you only need to hold at 20ppm. Given all that you've done I'd let it drop down to 10 and then do the oclt. If it fails then you haven't found all the algae.

You are testing oclt before any sun is around right? Sunlight can cause fc drops which is why it's an overnight test.

 

[727Pool_Life]

How much FC are you losing each night? How high are you taking it and what is your CYA level?

Maddie

I added to my OP that at one point I was as high as 57ppm of FC when slamming for mustard algae.

70ppm is the CYA

Chlorine level I have been maintain the past week has ranged from 34-41ppm. Well above the FC level for 70ppm CYA.

I am losing around 2-3ppm overnight, which is down from 4-6 I was at before so I have seen progress but this is insane, I need to buy stock in liquid chlorine manufactures at this rate.

 

[Poolzzz]

70ppm is the CYA

You said it was 50ppm in the thread...

 

[727Pool_Life]

Reading the thread it seems you've covered your bases assuming you've searched everywhere for hidden algae.

What fc level have you been doing your oclt at? Seems its up around 40ppm which is too high for a meaningful test. For a cya=50 you only need to hold at 20ppm. Given all that you've done I'd let it drop down to 10 and then do the oclt. If it fails then you haven't found all the algae.

You are testing oclt before any sun is around right? Sunlight can cause fc drops which is why it's an overnight test.

I am testing FC every 12 hours typically, 8am and 8pm. During the day I run my SWCG to maintain the FC which it can do and lately even adds FC so I know its gaining.

At night I turn it off around 6pm and stays off till I get a water sample for FC in the am.

You have a good point, what is the max level of FC that can be accurately tested with the kit? I know when it was over 40ppm I had some weird results at times when measuring.

- - - Updated - - -

You said it was 50ppm in the thread...

That was at the time and I wasn't as educated as to the shock I was using was adding CYA. I have since moved to liquid chlorine ....

Though I compensated the FC for the increase in CYA according to the table on the site

 

[Poolzzz]

OK on the cya.

Can you describe your oclt test? I sense some sunlight in the test and it may be a tad long. Is your pump running during the test?

At 40ppm fc you probably need extra powder but I'm not aware of a published upper limit. Hard to do better than 10% accuracy though.

Have you checked everywhere algae might hang out? Ladders, stairs, rocks, grout, light fixtures, mats, skimmers etc, etc.

 

[727Pool_Life]

I have three massive FL oak trees (screen enclosure so no debris in pool) that give good shade to the pool in the am and pm. During the am the sun may hit the pool water (we are talking a small percentage of the surface area, maybe 10%) for 10-15 mins depending on clouds and what time I get the sample, sometimes its 7:30 sometimes its 8 ( if I was off by .5-1 ppm in my testing I may factor in the partial sun but I'm losing 2-4, no way that much burns off in even 30-60 mins of sun exposure with my level of cya.) In the pm no sun hits the pool after about 6 pm, have a house next to me on that side that blocks sun in addition to trees.

No ladders or hand rails in pool, daily brush all steps, sides and walls of pool and spa. I cleaned out both light fixtures last week as well as the main drains (spa was disgusting). There is some mildew/algae in the grout/coping in some places but that is well above the water line.

Pump runs from 8am to 2am right now and is pushing about 60 gallons a minute (needed for pool heater). So I turn over the pool water roughly 6 times while running. All drains and returns are open and water is flowing through them all except the side port for the vacuum.

 

[Teald024]

It isn't unheard of to have the final portion of the SLAM process to take 2 weeks or longer. if you are still loosing 2-4ppm overnight, it could still be working on the last bit of algae & other organic stuff in the water. Keep with the SLAM process. You aren't going to use any less chlorine if you drop the FC down to maintenance levels. The downside is that you risk getting another algae bloom because you never completely cleaned the water. It's good to see the night time use dropping off. It will taper off to low to no FC consumption over night. Trust the process.

Tomorrow let the FC drop down to the advertised SLAM level. After dark, measure the FC level. In the morning, wake up early enough to take a sample before the sun hits the pool. Compare and see where you are. Let the pump run for at least 30 minutes each time before you take the sample and sample from the same location. Make sure the SWG isn't running between those 2 samples. You should turn the SWG off an hour before you take the evening sample.

You can swim in the pool if FC is below SLAM level, you can clearly see the bottom and your pH is within range.

 

[727Pool_Life]

It isn't unheard of to have the final portion of the SLAM process to take 2 weeks or longer. if you are still loosing 2-4ppm overnight, it could still be working on the last bit of algae & other organic stuff in the water. Keep with the SLAM process. You aren't going to use any less chlorine if you drop the FC down to maintenance levels. The downside is that you risk getting another algae bloom because you never completely cleaned the water. It's good to see the night time use dropping off. It will taper off to low to no FC consumption over night. Trust the process.

Tomorrow let the FC drop down to the advertised SLAM level. After dark, measure the FC level. In the morning, wake up early enough to take a sample before the sun hits the pool. Compare and see where you are. Let the pump run for at least 30 minutes each time before you take the sample and sample from the same location. Make sure the SWG isn't running between those 2 samples. You should turn the SWG off an hour before you take the evening sample.

You can swim in the pool if FC is below SLAM level, you can clearly see the bottom and your pH is within range.

I am down to 1ppm difference this am from last nights reading at 8pm. I got up late today but luckily there was cloud cover so no sun! I have gone this long whats another day or two to kill it all off....Is 0ppm FC lost at night achievable?

I am pretty good about taking the measurement in the same area and with water that is about 12 inches deep, not just the surface. Ill set the pump to run for an hour before I usually take the measurement and keep the SWCG off so chlroine can drop to 28-30ppm.

 

[YippeeSkippy]

keep in mind that when you overdose the pool in chlorine, you'll lose more at a time. It is just wasteful to go so far over the necessary amount of chlorine per your CYA.

The directions for mustard algae call for the extra high chlorine on those last days, not the entire SLAM process.

Maddie

 

[Mendy48]

Is your pump running 24/7 during the SLAM process, or is it set to turn off at a particular time?

I am down to 1ppm difference this am from last nights reading at 8pm. I got up late today but luckily there was cloud cover so no sun! I have gone this long whats another day or two to kill it all off....Is 0ppm FC lost at night achievable?

I am pretty good about taking the measurement in the same area and with water that is about 12 inches deep, not just the surface. Ill set the pump to run for an hour before I usually take the measurement and keep the SWCG off so chlroine can drop to 28-30ppm.

 

[727Pool_Life]

keep in mind that when you overdose the pool in chlorine, you'll lose more at a time. It is just wasteful to go so far over the necessary amount of chlorine per your CYA.

The directions for mustard algae call for the extra high chlorine on those last days, not the entire SLAM process.

Maddie

Makes sense, per poster above I turned of the SWCG for the day and had to add water due to evaporation so the FC should come down more into range of a normal SLAM for my CYA (28-30ppm), tonight will hopefully be the last test I have to conduct.

Is your pump running 24/7 during the SLAM process, or is it set to turn off at a particular time?

Runs 8am to 2am (so its off for 6 hrs)

 

[Mendy48]

When you're SLAMing your pool, it's recommended that you leave your pump running for 24hours. Proper circulation/filtration of the pool water is needed during the SLAM process. Running your pump 24hours is one of the is a prerequisite for the SLAM process. Please your pump running 24hours until your SLAM process is complete.