How to balance killing algae and accurately testing CYA and pH levels when opening pool

[jmb]

We have been successfully following the SLAM process for opening our pool annually. This is the first time in several years that we have significant algae when opening the pool.

I understand the SLAM process but this year I am a bit stumped. In the past without algae issues we ran the filter for 24-48 hours, brushed the walls and vacuumed on waste a few times to remove debris and dirt from pool before testing for CYA and pH prior to initiating a very short SLAM process.

My question is; How do we balance killing algae and accurately testing CYA and pH levels when opening the pool?

It seems that we need to kill the algae with chlorine followed by brushing, vacuuming on waste and running the pool filter in recirculate mode first before testing CYA and ph and starting the SLAM process to be sure we have killed all the algae..

The SLAM process explains how much chlorine to add based on CYA level; but, how do we determine how much chlorine to add to kill the algae before we can accurately follow the SLAM process and accurately assess for CYA and pH levels.

Thank you!

 

[PoolStored]

The SLAM process explains how much chlorine to add based on CYA level; but, how do we determine how much chlorine to add to kill the algae before we can accurately follow the SLAM process and accurately assess for CYA and pH levels.

You don't.

Raise your CYA up to 30ppm. Lower your pH to 7.2-7.4 and start the SLAM.

Print the SLAM process page, and keep it with you, makes it a handy reference standing by the pool and gives you step by step guide while you are out there, without having to remember it or trapse back to the computer. Link-->SLAM Process

 

[JoyfulNoise]

Not sure what your question is …

You measure CYA and pH before you add chlorine, adjust as-needed, and then don’t bother measuring them again until the SLAM is complete. Doing all that brushing and cleaning initially is fine as it takes out any solid debris that might cause some additional chlorine loss. But the point of the SLAM is to kill the algae and oxidize organic waste.

 

[jmb]

My question is that we just removed our pool cover and opened the pool. The filter has not been running. I will not get accurate readings when testing for CYA and pH until I have run the pool filter for 24- 48 hours. In the past when we have opened the pool without algae we have been able to run the filter for 24 -48 hours and remove debris before testing for CYA and pH and starting the SLAM process to be sure we do not have any algae. This year we know we have algae and it seems pointless to run the filter without adding chlorine to kill the algae before I can actually get an accurate CYA and pH reading. In the past when I have tested for CYA and pH without running the filter first my readings have been not been accurate.

I hope this helps to add clarity to my question.

Thank you.

 

[PoolStored]

Add 3ppm of liquid chlorine to the pool. This will stop the algae growth. Run the pump for 12-24 hours, test and start the slam.

 

[JoyfulNoise]

You can run the pump/filter for a few hours and then test. If you want to get more mixing, scrub the liner with a pool brush or use your leaf net/rake to mix the water. There’s nothing about the algae presence that is going to make any difference to the testing or the course of the SLAM. You might load up the filter a bit with algae … who cares, just backwash it. Once you get your pH and CYA numbers, adjust and move on to the SLAM.