Fighting Algae w/ SLAM methodology questions

[bradleyofkansas]

I recently allowed my CYA levels to creep into the 150's and it backfired with algae outbreak. After diluting and refilling, got my CYA back to 56 (manageable I believe). Since then, I've been fighting with shock (shocking w/ 3lbs ever 12 hours for the last 48 hours) to get back to normalcy, but since it's not working I think it's time to try SLAM for the first time. (I'm a brand new member.) My levels are currently good (CL: 6.4, pH: 7.4, Alk: 90, CYA: 56 17,000gallon inground pool), so I think I'm ready, but before I start I have a few questions.

For my SLAM treatment:
1.) Considering I have to maintain a higher FC level with 56 CYA vs. a lower CYA, is it more cost effective to start slam now, or get my CYA even lower for a better starting point to decrease expenses needed to cover Chlorine costs? (Water cost vs. Chlorine cost)
2.) In the SLAM instructions, in the "You are Done" section, do ALL those criteria need to be met, or just 1 of them?

• For the overnight loss test how am supposed to conduct that if I'm needing to maintain a CL of 24ppm. Do I wait to do that until visible algae is gone?
• If I am looking for a CL loss of less than 1.0ppm overnight, How long might it take for that that CL to drop to a swimmable level? And what do ya'll consider a swimmable level (Forget minor irritations, I'm not worried about that)?

Thanks in advance. Excited for happier pool days ahead.

 

[mknauss]

Welcome to the forum!
Can you tell us what test kit you are using to get your pool water chemistry results? Include that in your signature, along with pool type, volume, equipment, etc.
IF your CYA is 60 (round up), then a SLAM level FC of 24 ppm is not out of the question. So draining the pool to reduce the CYA is up to you.
All three criteria are to be met to pass the SLAM process.
Once you get crystal clear water, then you do a OCLT.
You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.
I suggest you read ABC's of Pool Water Chemistry.

 

[bradleyofkansas]

Welcome to the forum!
Can you tell us what test kit you are using to get your pool water chemistry results? Include that in your signature, along with pool type, volume, equipment, etc.
IF your CYA is 60 (round up), then a SLAM level FC of 24 ppm is not out of the question. So draining the pool to reduce the CYA is up to you.
All three criteria are to be met to pass the SLAM process.
Once you get crystal clear water, then you do a OCLT.
You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.
I suggest you read ABC's of Pool Water Chemistry.

It is a Taylor K-2006C with FAS-DPD chlorine.

 

[bradleyofkansas]

@mknauss if you were to guestimate how many 1 gallon jugs of liquid chlorine I should get for this process, what would you say? Just trying to limit runs to walmart. Also, how much would you start with before testing after 1 hour?

 

[cowboycasey]

We can not say how many as each and every SLAM is different... I would start with 12 gallons, 3 cases and see where that gets you

 

[mknauss]

It will take 4 gallon of 10% liquid chlorine to raise your FC to 24 ppm. Depending on the condition of your water, it can easily take 4 gallons a day for a couple days and then it should start to reduce over time. A total of 15 to 20 gallons could easily be needed.

 

[bradleyofkansas]

It will take 4 gallon of 10% liquid chlorine to raise your FC to 24 ppm. Depending on the condition of your water, it can easily take 4 gallons a day for a couple days and then it should start to reduce over time. A total of 15 to 20 gallons could easily be needed.

One last thing, I’m about to start with 4 gallons. While I plan to keep a very close eye on the levels to maintain 24ppm, when is a reasonable time to do my first check, before I start over adjusting too soon?

 

[JJ_Tex]

One last thing, I’m about to start with 4 gallons. While I plan to keep a very close eye on the levels to maintain 24ppm, when is a reasonable time to do my first check, before I start over adjusting too soon?

I personally would double check that you hit 24ppm 30 mins after the first addition. Then test 4 or more times a day and add as needed, until you are done.

 

[mknauss]

Check it every couple hours (excluding overnight) for the first day and then you can stretch that out once you see the FC holding better. 3 to 4 times per day is a good minimum number of times to test and add.

I suggest ordering reagents now - you will be using them up pretty fast for the FC test.

 

[bradleyofkansas]

Check it every couple hours (excluding overnight) for the first day and then you can stretch that out once you see the FC holding better. 3 to 4 times per day is a good minimum number of times to test and add.

I suggest ordering reagents now - you will be using them up pretty fast for the FC test.

Thanks @mknauss . I did re-order today, then I rechecked the shipping date cause I neglected to look before I purchased. Looks like I'll need to make a run to my local pool store tomorrow to stock up. Can't wait till Aug. 28th.

 

[mknauss]

I will be amazed if a pool store carries the R0870 and R0871. Be careful.

Did you order from TFTestkits.net? They ship quickly if possible.

 

[bradleyofkansas]

@mknauss @JJ_Tex
It's been about 14 hours since I started SLAM. All stats were inline before I got started, I brushed, vacuumed and backwashed. Should I be alarmed that the only chlorine loss I've had over that time is 26 down to 24.4? I know the ultimate goal is to have little to no chlorine loss towards the end of the process. But it seems early and that the algae should be consuming more of the chlorine?

Aug. 20th 8pm - 4 gallons liquid chlorine
Aug. 20th 1150 pm - 26 ppm
Aug. 21st 430am - 24.4 ppm
Aug. 21st 830am - 24.4 ppm

Thanks in advance

 

[Chasarms]

@mknauss @JJ_Tex
It's been about 14 hours since I started SLAM. All stats were inline before I got started, I brushed, vacuumed and backwashed. Should I be alarmed that the only chlorine loss I've had over that time is 26 down to 24.4? I know the ultimate goal is to have little to no chlorine loss towards the end of the process. But it seems early and that the algae should be consuming more of the chlorine?

Aug. 20th 8pm - 4 gallons liquid chlorine
Aug. 20th 1150 pm - 26 ppm
Aug. 21st 430am - 24.4 ppm
Aug. 21st 830am - 24.4 ppm

Thanks in advance

You must not sleep much!!

 

[mknauss]

Keep brushing and look for hidden areas of algae (skimmer doors, throats, light niches, ladders, etc).

 

[bradleyofkansas]

Keep brushing and look for hidden areas of algae (skimmer doors, throats, light niches, ladders, etc).

Will do. But nothing to be alarmed about? Or does this sound abnormal?

 

[bradleyofkansas]

You must not sleep much!!

I'm just so over my algae issue and willing to do almost anything at the moment. Gotta stay committed. I'm done wasting money

 

[mknauss]

The lower FC loss just implies that you do not have a large organic load in the pool. That is a good thing. Maintain the SLAM level FC today. If FC loss continues to be low and you have a crystal clear pool (no algae or debris either) then do a Overnight Chlorine Loss Test