Raised free chlorine to 31ppm and still algae persists

[Ttub44]

Hi,

I have been slamming my pool for a little over a week now with little to no changes other then the reduced thickness of my wallet. At this moment the ph is at a fair level of around 7.7 (when I checked before slamming about 2 weeks ago) cya is at 46ppm, and free chlorine is at 31ppm (Recommended shock level is 18ppm with regard to the cya level) and .25-.5 combined chlorine, I have not tested calcium hardness but have noticed some light scaling at around water level. I have been brushing everyday, backwashing about every 3 days as the filter pressure gauge indicates it is necessary, but have yet to vacuum. Testing has been done with a new Taylor 2006 kit, fc added through use of 10% pool chlorinating liquid from Walmart, and the pool is roughly 16,000 gallons. Pool filter sand was changed last year, and a broken lateral was replaced a few months ago, the pressure from the return is good. With regard to climate and temperatures, I live in Nebraska.

The recommend dosing provided by the pool math calculator for free chlorine has been having little affect on the chemical level, thus requiring me to add two to threes times the recommended dose to get the wanted results with regard to free chlorine (ie. to get from a FC of 14 to 18 I was told to add 2 quarts of 10% bleach, but I added 4 gallons and withing 16 hours the FC level was 15ppm, with .25 CC), it also hasn’t been able to maintain the levels very well either, which has me confused as cya is at a good but slightly high level, and combined chlorine is rather low. Over the last two days I have maintained a shock level of 18ppm FC with no results, so last night (14 hours ago) I added 8 gallons of 10% chlorine on recirculate, I have just recently tested the pool and the FC is at a level of 31ppm and the pool looks like the photo provided. The only changes I have noticed is most all the insects have been eradicated and algae is not showing up much in the basket anymore. I am at a point where I have spent a few hundred dollars on chlorine already and am about at wits end as no amount of chemicals seem to be helping. I was waiting until I could at least see the bottom to vacuum, and figured I should probably do it sooner, but I guess I’ve felt if nothing else has had an affect it wouldn’t make a difference either.

I was recommended by someone on /pools on Reddit to raise to shock level, recirculate the water for several hours, brush the pool, then turn the filter off for 24 hours, after which I will add floculent, recirculate for 4-5 hours, then turn off the pump and once all the algae has dropped vacuum to waste. I was apprehensive about listening to this advice as I often hear not to use floc, but so many others seemed to encourage me to follow these directions. I wanted to get a second opinion before I went down this path, so what do y'all think I should do?
thank you

 

[HermanTX]

Welcome to TFP.
On this forum we do not recommend the use of Floc.
We do recommend the SLAM Process which you seem to trying to follow but not exactly.
We would call your CYA 50 and therefore need a FC level of 20ppm. The key part of a SLAM is to MAINTAIN the level of 20. So that means testing every 3-4 hours during daylight. There are 2 things consuming your FC, the UV (during the day0 and the algae. So it is expected that FC will decline after you add LC which is why it is recommended to test every 3-4 hours and bring that FC back up to SLAM level - 20ppm for your CYA.

There is no reason to test CH and most pH tests with FC above 10ppm cause skewed readings. We request that pH be lowered to 7.2 BEFORE you start the SLAM for these reasons.

It is important to brush throughout the process and try to vacuum to waste if feasible. Also try to pick up debris off bottom with a net.

There is no firm timetable for a SLAM. But it you follow the process, it has proven to work for 100's maybe 1000's of members on this forum.

 

[Ttub44]

Welcome to TFP.
On this forum we do not recommend the use of Floc.
We do recommend the SLAM Process which you seem to trying to follow but not exactly.
We would call your CYA 50 and therefore need a FC level of 20ppm. The key part of a SLAM is to MAINTAIN the level of 20. So that means testing every 3-4 hours during daylight. There are 2 things consuming your FC, the UV (during the day0 and the algae. So it is expected that FC will decline after you add LC which is why it is recommended to test every 3-4 hours and bring that FC back up to SLAM level - 20ppm for your CYA.

There is no reason to test CH and most pH tests with FC above 10ppm cause skewed readings. We request that pH be lowered to 7.2 BEFORE you start the SLAM for these reasons.

It is important to brush throughout the process and try to vacuum to waste if feasible. Also try to pick up debris off bottom with a net.

There is no firm timetable for a SLAM. But it you follow the process, it has proven to work for 100's maybe 1000's of members on this forum.

Thank you for taking the time to respond, I was happy to find out literally a day after posting this thread the pool when from radioactive green to mint green, and now Gatorade cool blue. Thank you!

 

[PoolStored]

it has proven to work for 100's maybe 1000's of members on this forum.

10s of thousand to 100s of thousands, actually.

 

[Jsf721]

I just finished a mini slam. If its not working you are missing something, or not following closely enough, or your testing is off..

You need to really focus on maintaining the FC at the SLAM level for your CYA consistently over each day until you win. I think of it like WAR. Me vs Algae. I need my soldiers to be stronger, for longer to defeat the Algae. I cannot let my weapon, FC be degraded by UV, Algae or other contaminants. With a Pool that's visibly soiled you need to check FC levels every few hours and when it starts to clear keep it up until you do not loose any FC for one overnight cycle. Maintain until sun does down and check FC and then check before sun up. If its the same, you are done. Once it clear to your eye, and FC does not drop I usually just keep slam level for 24 more hours but only check morning and evening.

 

[reggiehammond]

I just finished a mini slam. You need to really focus on maintaining the FC. With a Pool that's visibly soiled you need to check FC levels every few hours and when it starts to clear keep it up until you do not loose any FC for one overnight cycle. Maintain until sun does down and check FC and then check before sun up. If its the same, you are done. Once it clear to your eye, and FC does not drop I usually just keep slam level for 24 more hours but only check morning and evening.

While I agree that FC level maintenance is the key to SLAM, I would caution that there's no such thing as a "mini SLAM."

I also agree that holding SLAM an extra day is not a bad idea, but there are also 3 exit criteria to confirm the SLAM process is complete that requires diligence and testing, not just passing an OCLT.

1) CC's at 0.5 or less
2) Pass OCLT
3) Water crystal clear, no visible algae

 

[Jsf721]

While I agree that FC level maintenance is the key to SLAM, I would caution that there's no such thing as a "mini SLAM."

I also agree that holding SLAM an extra day is not a bad idea, but there are also 3 exit criteria to confirm the SLAM process is complete that requires diligence and testing, not just passing an OCLT.

1) CC's at 0.5 or less
2) Pass OCLT
3) Water crystal clear, no visible algae

I agree, the visually clear piece to me is assumed, and the CC yes I also agree.

 

[hexabc]

10s of thousand to 100s of thousands, actually.

I’m embarrassed Since I started following the rules of TFP in 2017, my pool never went green and I didn’t have a chance to go through the SLAM process even once.

 

[duraleigh]

Agree with Reggie on the "mini" SLAM. Reminds me of the old adage, "You can't get a 'little' bit pregnant"

By far, the most common error in the SLAM is folks taking short cuts. It just doesn't seem to work. Follow the exact wording, dosage and intent of the SLAM article.......it won't let you down.

If the SLAM is much over a week or so, I will bet money the SLAMmer has skipped a step or two.

 

[Jsf721]

Agree with Reggie on the "mini" SLAM. Reminds me of the old adage, "You can't get a 'little' bit pregnant"

By far, the most common error in the SLAM is folks taking short cuts. It just doesn't seem to work. Follow the exact wording, dosage and intent of the SLAM article.......it won't let you down.

If the SLAM is much over a week or so, I will bet money the SLAMmer has skipped a step or two.

My reason for calling it a mini slam was it was not a green (or mustard algae) pool like what I had before knowing what CYA was and why that number mattered.

This time I caught it a the dust and small amount in corners. I still SLAMED is to spec and by the book it was just over much quicker this time and I extended it one more day just to be sure. Its now cooking off to normal FC levels and I need to be careful to catch it before it dips too low. I was at 16 this morning and hope to be at 11ish Friday when I return to the house. Being off site makes this even more of a challenge.

 

[duraleigh]

Being off site makes this even more of a challenge.

No doubt about that but it sounds as if you are in the home stretch......nice work!