Getting ready to SLAM

pypeke

Silver Supporter
Jul 31, 2015
283
Southeastern Oklahoma
I know that I need to adjust pH before SLAMming the pool, but what about CYA? THE FC/FYA chart does not go to zero CYA so I don't have a starting point for SLAM FC. Maybe FC SLAM @ 10-12?

After adjusting pH from 7.2 to 7.5...
1. Should I then add stabilizer to about 30, then start the SLAM process?

Or should I start adding liquid chlorine without adding stabilizer? The organics and the sun will use the chlorine quickly unless I add stabilizer, right?

Vinyl liner- in ground, play pool, shallow (3ft) in 2 ends and 6ft deep in center.
pH - 7.2 (will bring up to about 7.5)
TA - 40 (will bring up to around 100 after SLAM)
FC - 0 (maybe 10-12? for the SLAM?)
CYA - 0 (maybe shoot for 30? 40? 50?) in SE Oklahoma between 70°-85° air temps currently.
CH - 125 (old chemicals though. Do I even need to test for this with a vinyl pool? )


Refresh my memory...Phenol Red is???? I have one bottle of it and one bottle of R-0014. The same thing? Different?

Last question...on Pool Math....when it says temperature, I assume it means water temp, not the air temp. Am I right?

Thanks!
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
17,034
Evans, Georgia
Before you add any CYA, do this- Add 10ppm of liquid chlorine to a running pool and let it mix in for 10 minutes. Retest it and if you still have most of that 10ppm FC, go ahead and raise your CYA up to 30ppm.
If you have zero FC after 10 min, come back and tell us.
 

pypeke

Silver Supporter
Jul 31, 2015
283
Southeastern Oklahoma
Thanks.

"Add 10ppm of liquid chlorine to a running pool and let it mix in for 10 minutes."
I am not sure what that means. The pump is running, but "add 10ppm" is confusing me. Do you mean add liquid chlorine like I am doing a FC slam of 10? I am probably not saying that right....
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
17,034
Evans, Georgia
Do you use PoolMath? Lemme figure it out for ya...Ok, 196 ounces of 10% LC will give you 10ppm FC. All I'm trying to do is figure out what happened to last years CYA? Its odd tht it is entirely gone. To rule out bad reasons we can test with chlorine and if all the FC disappears in ten minuts its possibly a bad reason. If you still have some in 10 min time... Its time to SLAM!
 

IceShadow

Gold Supporter
TFP Guide
Jun 8, 2019
2,609
Milwaukee, WI
Pool Size
20000
Surface
Vinyl
Chlorine
Liquid Chlorine
What YS is having you do is test to make sure your pool doesn’t have a bacteria that converts CYA to ammonia. No FC and no CYA are potential indicators. It’s rare but if you do have that and add CYA it would make the issue worse so we want to rule it out first. :)
 

CrystalRiver

Well-known member
Jun 19, 2020
648
Massachusetts
I know that I need to adjust pH before SLAMming the pool, but what about CYA? THE FC/FYA chart does not go to zero CYA so I don't have a starting point for SLAM FC. Maybe FC SLAM @ 10-12?

After adjusting pH from 7.2 to 7.5...
1. Should I then add stabilizer to about 30, then start the SLAM process?

Or should I start adding liquid chlorine without adding stabilizer? The organics and the sun will use the chlorine quickly unless I add stabilizer, right?

Vinyl liner- in ground, play pool, shallow (3ft) in 2 ends and 6ft deep in center.
pH - 7.2 (will bring up to about 7.5)
TA - 40 (will bring up to around 100 after SLAM)
FC - 0 (maybe 10-12? for the SLAM?)
CYA - 0 (maybe shoot for 30? 40? 50?) in SE Oklahoma between 70°-85° air temps currently.
CH - 125 (old chemicals though. Do I even need to test for this with a vinyl pool? )


Refresh my memory...Phenol Red is???? I have one bottle of it and one bottle of R-0014. The same thing? Different?

Last question...on Pool Math....when it says temperature, I assume it means water temp, not the air temp. Am I right?

Thanks!
1. No reason to adjust pH when it's at 7.2. It will want to come up on its own over time anyway. That said ...
2. Bump your TA up to 50 before you SLAM. When TA is below 50, you don't have enough buffer, and your pH can crash from any additions such as CYA or acid rain.
3. Follow the FC/CYA chart once you have added some CYA.
4. If you don't have a heater or SWG, with a vinyl pool you don't need to worry about CH.

Pool Math is asking for the water temp, correct. It's used for calculating CSI. If no heater and no SWG and a vinyl pool, you don't need to worry about CSI. You can turn CSI and temp off in the settings.
 

pypeke

Silver Supporter
Jul 31, 2015
283
Southeastern Oklahoma
Ah, gotcha! The chlorine was still there after 10 minutes, so I started SLAM. Currently is is a little cloudy, but it has only been 2 days. Will keep chlorine high for several days.

I need to raise the TA though. Will do that today.

I don't know why the CYA is always zero, but it is zero every year when I open the pool.

My test chemicals are not a year old yet, but I ordered replacements from tfttestkits yesterday. So, I will not add CYA until the new chemicals come in.

Thanks.
 
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