First SLAM critique


Feb 3, 2019
SW Florida
After nearly 6 years of pool ownership I ran across an issue of light haze in the water. I cranked up the SWG and the haze persisted. I had the SWG maxed at 100 % and was seeing FC at 6-7 and CC of 0.5. I was also seeing a good deal of fine dusty looking material when I brushed the pool. I added chlorine to about 10ppm and the haze remained so I suspected is it was time to SLAM.

Thanks to TFP, I followed their guidelines. My pool data prior to the SLAM:
FC 10.5, CC 0.5, pH 7.4, TA 90, CH 325, CYA 50, Salt 3300

I turned off the SWG and brought the FC up to 22.0 and held it in that range for a couple days then did the first OCLT which was 2.75. I kept the FC at 22.0 for another two days and the OCLT test was 0.25.

*** SLAM done ***

I brushed daily with a mixed wire, nylon brush and ran the pool vac for a few hours as well. I pulled the pool filter cartridge and cleaned it and it was pretty dirty considering I had done this just prior to the SLAM.

Post SLAM pool data:
FC 21.75, CC 0.25, pH 8.0, TA 115, CH 350, CYA 40, Salt 3400

I added stabilizer to bring the CYA and pH in line plus 2 lbs of Calcium Chloride for the CH.

Current pool data:
FC 12.0, CC 0.0, pH 7.4, TA 90, CH 375, CYA 70, Salt 3400.

Not yet time to turn the SWG back on. In hindsight, I should have waited to add the stabilizer until the FC had come down at least into the single digits. But hey, this was my first SLAM and I’m learning, thanks to the help of TFP.

The water is now so clear now it sparkles.

I’m not sure what the issue was but I assume it may have been mustard algae. I’m just not experienced enough to spot this visually. I am anal about testing the pool almost every day so I was surprised that this haze occurred but in a way, I’m pleased that I had the experience of performing a SLAM and I’m very happy with the results.

Any critique from you pros? Things I may have done right or wrong? Spot any glaring mistakes or suggestions for my edification?

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Gold Supporter
May 20, 2020
Katy TX
Pool Size
Liquid Chlorine
Good info - thanks for providing your results and process.
Key point was that pH pre-SLAM was 7.4. Note that testing pH when FC is above 10ppm does not provide accurate results if using the drop method. However, if you have a pH meter that is valid for high FC levels is fine.

Interesting to note that your CC in pre-SLAM was only 0.25 yet when you did your first OCLT it was 2.75 change. I would have thought that your CC pre-SLAM would have been higher. Just my perspective.


Gold Supporter
TFP Guide
Jun 16, 2019
Things I may have done right or wrong
You followed through with the process, which is why it worked. You brushed and vac’d daily and kept at it. Well done.

Also wanted to point out that your cartridges made it through the process. If they are big enough they don’t need babysitting like sand and DE might. Mine performed the same. Cleaning the filter was an after thought..... oh yeah, I should do that. And when I did clean them they much less dirty than my regular cleanings. (Mine started the process fresh too so it was all SLAM) It allows more free time to spend on the SLAM process. One more huge vote for honkin cartridges IMHO.
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