First SLAM

[yann]

Hi all

I have been away from home and came back on Monday to a pool full of debris from the recent high winds, and a FC at 4 for a CYA at what I thought was 80 (tested today at 70)
Vacuumed the pool and cleared floating debris
Raised the SWG to 100% for 24h/day
Tuesday FC was still at 4 and today at 6.5.
Also noticed large green patches at the bottom of the pool when I got home tonight.

So I believe it's time to SLAM.

Pre SLAM at 18.30
FC 6.5
CC 0
pH 7.2 (down from 7.8 with MA)
CYA 70

Added 6000ml of LC 12.5% and turned SWG off, pump running 24h/day
Brushed the pool, insisting on green patches

At 19.30, FC is above SLAM Level of 28 at 33.

Happy to take advice / recommendations

Thanks

 

[yann]

I’ve ordered more FAS-DPD as I might run out
in the meantime is it ok to use a 5ml sample and count 1ppm/drop?

 

[kimkats]

I came looking for this thread when I saw your post in "what did you do to your pool today"

You can and should use the 10ml sample and count 1ppm/drop. It uses less test stuff and is good enough to do a SLAM. I don't think you should drop it down to 5ml samples.

You have a good start on the SLAM. Thank goodness you know about TFP and how to SLAM.

I am going to give you some pointers:

-M=maintain as in make sure to maintain the FC at SLAM level. That will get it over faster.

-Testing-test and redose at least 4 times a day. It will be hard if you work outside the home but can be done. Morning, right when you come home, dinner time, right before bed.

-brushing at least once a day, twice if possible. This gets the algae into the water to be filtered out.

-filter-24/7 like you are doing already. Watch the pressure and back wash when it goes 20% over your clean pressure or if you notice a loss of return flow.

-Swimming-it is safe to swim if the FC is just below your SLAM level for your CYA levels.

-don't bother testing anything other than FC every time. You can test the cc every once in a while if you want to but really no need until you are close to being done.

-test the FC about 30 mins after adding to make sure your chlorine is at the % you think it is. You will only need to do this the first time then every once in a while. We had one SLAM take forever and it turned out their chlorine was not as strong as they thought it was.

It looks like you caught it early so it should be a fast one.

Kim

 

[yann]

Hey,

Thanks for your advice!
My test kit says 10ml sample will give me 0.5ppm/drop, that's why I was asking if it's ok to use 5ml sample and 1ppm/drop. BTW I'm only testing for FC ATM

LC strength seems to be as labeled, pool maths gave me an original drop of 6200ml, I poured 6000ml in and got FC 33 instead of 28.

Re FC, I tested every hour so far and 20.30 was 29ppm and 21.30 25ppm
I just added 900ml of LC and gave it a good brush again.

It's hard to tell in the dark but it looks like the green patches have gone.
However the FC is being consumed at a 4ppm/h rate so there is definitely something nasty in there.

I'll try to Maintain as much as possible tonight and overnight as there will be no one home tomorrow to test and add LC.
I'll resume when I get home tomorrow.

Thanks again for your help and support

 

[kimkats]

I would look at your swg while you doing this. How did it let your fc get below your target level while you were gone?

 

[yann]

I would look at your swg while you doing this. How did it let your fc get below your target level while you were gone?

Good point.

I guess I am still trying to fine tune SWG run time / pump time.
From my records, it looks like I had dropped the % a little to let the FC come down from 10, and I forgot to tune it back up.
With all the debris that were dropped in the pool over the weekend, I guess that was enough to consume too much FC.
Also I suspect the kids let the dog in the pool as I found some hair in the skimmer basket.

Still, good idea to have the cell tested. Is the pool $tore the best place for that?
Since I inherited pool and equipment when I bought the house, I am not sure how long the cell has been there, and how well it has been treated.
I remember the previous owner told me: "run the pump 6-8h a day with the cell at 100%, then take a sample to the $hop once a week and they'll tell you what you need to do"

 

[yann]

My test kit says 10ml sample will give me 0.5ppm/drop, that's why I was asking if it's ok to use 5ml sample and 1ppm/drop.

Am I correct on this one??

Thanks

 

[Jezza]

Yep correct Yann. 5ml sample is 1 drop is 1.0FC. Just keep in mind that you must use the 10ml sample when conducting the OCLT.

 

[yann]

Thanks Jezza!

i did a 5ml and got consistent realistic results so will stick to that until tomorrow evening when I would expect to do an OCLT. And yes I knew I had to use a 10ml sample for that, thanks for the reminder.

At at the moment I am still losing around 4ppm/h, just adjusted back to SLAM level with 900ml of LC.

Is is worth adding 20ppm of LC now to cover the overnight loss until tomorrow morning?

Or should I let my FC drop overnight and adjust in the morning?

 

[mknauss]

Up to you but I doubt a Overnight Chlorine Loss Test is in order for several days. SLAM Process typically takes up to a week. Very unusual to be done in just a couple days.

On your last test and dose of the night just take it to shock level. No need to go over. You are still killing algae even below shock level, just not as fast.

Take care.

 

[Jezza]

Yes I agree with Marty- I think that if your losing 4FC per hour, you can expect around the week mark- perhaps 4 or 5 days if your lucky. Keeping up the testing/re-dosing as much as possible will help things move along.

 

[yann]

Thanks

5.30am results show FC 28
Repeated the test with 10ml sample and got 28 again, which is a 0 FC loss since my last addition at 11pm (6.5h)

I'm off to work now and I'll be back in 12h, should I add some LC for the day, or leave it since I'm at SLAM level right now?

Thanks

 

[kimkats]

I don't think there is a "test" of the cell. I am not sure. I will do some digging around to see what I can find.

How to test SWG before replacing cell

Testing SWG Salt cell

There are a couple of older threads that might give you some ideas. See what you think and we can go from there.

Kim

 

[yann]

Thanks for that.

I'll try testing the cell over the weekend, I'm sure it's ok to have the pump off for an hour or 2 while the cell is disconnected.

Brief update on the SLAM:
Last LC addition was 11pm on Wednesday.
FC was 28 at 5am today, 18 at 6pm. Added 3000ml of LC 12.5% to bring FC back up to 28.
Pool was crystal clear (always was BTW), the green patches looked a lot more faint, but still visible.
Brushed walls & floor and vacuumed to filter.
Filter pressure ok.

At 8pm, FC was still at 28, only brushed the floor again.
At 10pm, FC at 27, added 300ml LC 12.5%
Brushed floor again, mostly where the patches are.

Call it a night, will test again at 5am tomorrow and add LC if needed.

What are your feelings about this SLAM?

Also can I test for CYA during a SLAM? I just want to be sure I've got my FC right. My pre-SLAM test yesterday was done in less than ideal conditions: end of day, sun not at the highest.

Thanks

 

[mknauss]

You can test your CYA during the SLAM.

Pretty typical SLAM. Go until you meet ALL three criteria as shown in the SLAM article.

Take care.

 

[yann]

Thanks Marty,

I’ll check my CYA tomorrow.

FC holding quite well. Only lost 6ppm in 24h

might try OCLT tomorrow night.

 

[Chris W]

Thanks Marty,

I’ll check my CYA tomorrow.

FC holding quite well. Only lost 6ppm in 24h

might try OCLT tomorrow night.

Probably too early to do Overnight Chlorine Loss Test you are still losing ~2ppm every 8 hours, needs be < 1 in 8 hrs

I just finished my 1st SLAM Process and was reminded to use POP
Pool Owner Patience
It will get there.
It won't hurt if go an extra day
Took mine 7 days exactly.

Chris

 

[yann]

Hi all,

Sorry been busy.
Quick update.

Been passing OCLT for a couple of nights now, but still seeing my patches at the bottom of the pool. They're very light and faint but still there
Thinking of raising FC to Mustard levels for 24h and see if it makes a difference.

Is that ok?

 

[mknauss]

You can take it up to a higher FC level. If it reacts, then it is because your CYA test is inaccurate and your shock FC should have been higher.

Let the FC drift back after raising it to that high level.

Take care.

 

[yann]

Why is it unsafe to swim if FC is above SLAM level?

hot day today. Wife and kids want to jump in.
Told them it’s not safe but I actually don’t know why.

Short answer is fine

thanks