When to stop SLAMing

[Poolecw]

Second year pool owner. Last year was a breeze with no problems what so ever.

Last week was VBS at my church so didn't have the chance to go out to take a look at my pool's condition. Saturday morning, I go out to find that the pool was covered with mustard algae. I immediately brush it down, test all my levels and start the SLAM process.

Initial test results:
FC: 3.0
CC: 0.5
pH: 7.8 (added muriatic acid to bring to 7.3)
TA: 60
CYA: 35

Using the PoolMath app to determine the SLAM FC level, I added 10% bleach to bring the level up to 14.0

Since Saturday (today is Tuesday morning), I worked to maintain 14.0 FC. Daily, I also vacuumed dead algae, brushed the pool, backwashed, and kept adding chlorine as needed.

Currently, I am no longer seeing any living algae. The water is cloudy but improving. I assume dead algae suspended in the water is causing the cloudiness.

Questions:
Am I ok to stop SLAMING and bring the FC back down?
When SLAMING is done, do you recommend keeping FC slightly higher than normal for a while?
Do you recommend Diatomaceous Earth or a clarifier to help clear up the water?


Thanks all

 

[JJ_Tex]

Keep at it until you pass the 3 criteria to end the SLAM:
- Water is clear
- CC is 0.5 or lower
- You pass an Overnight Chlorine Loss Test (OCLT)

You are at the point where people start to get a bit impatient, but trust the process.

SLAM - Shock Level and Maintain

We’ve all had to deal with a green pool. Clear algae from your pool with a SLAM! Read here to use shock level and maintain to clear your pool.

www.troublefreepool.com

 

[Poolecw]

Thanks. I'll perform the OCLT tonight. I didn't do the test last night because it was pouring rain here and it would probably effect the results.

 

[JJ_Tex]

How does your water look today? Previously you described it as cloudy. If it is still cloudy, I would say to wait another day to do the other tests.

Also I just noticed that you said your CYA was 35. Typically you want to round up CYA, so treat it as 40 which means your SLAM target is a bit higher at 16.

Regardless, it sounds like you are in the home stretch.

 

[Mdragger88]

35 ppm cya is not a readable measurement as the test is not logarithmic so if you are in between 30 & 40 you round up to 40 therefore your SLAM Process level is 16ppm.
As stated above- keep going until u pass ALL 3 end of slam criteria.
*crystal clear water
*Cc of .5 or lower
*Overnight Chlorine Loss Test of 1 or less

 

[Poolecw]

Thanks all.....

The water clarity has improved but still not clear.

I will increase FC to 16 and continue to rock on. However, I am using the PoolMath app. It told me to take it to 14. I guess it doesn't round up CYA

 

[Msch99]

Probably the app uses percentage, enter 40 and you should get the correct FC levels.

 

[Poolecw]

Probably the app uses percentage, enter 40 and you should get the correct FC levels.

It appears that the app pulls the CYA based on the last test log. So, it pulled a CYA of 35 as used it in determining the proper SLAM FC rate. However, it does allow you to override the CYA value.

 

[Mdragger88]

It appears that the app pulls the CYA based on the last test log. So, it pulled a CYA of 35 as used it in determining the proper SLAM FC rate. However, it does allow you to override the CYA value.

You can change your log entry to 40 so it will be automatic
Go to logs- hit the entry you wanna change, change the parameter (cya) to 40 , hit the check mark @ the top

 

[Poolecw]

Passed the OCLT as well as the other criteria for a successful SLAM. Lets NOT have to do this again!

Thanks all.

 

[Newdude]

Well done !!!

Lets NOT have to do this again!

that’s totally on you. You see the minimum on the FC/CYA Levels ? The word minimum doesn’t not convey the gravity of the situation. Don’t touch it. Don’t approach it. Don’t DREAM of it. Stay in target range, even after your daily FC loss.

Regular testing will give you all the red flags to spot any trends long before there is an issue. Adjust your routine as needed and be trouble free.