Help Getting the SLAM Process Right to Kill Algae Problem

Asian Dude

Member
Jun 23, 2023
7
Lansing Michigan
Opened to a green pool which is probably due to high CYA after years of Chlorine Puck use. They were 115 ppm before. After draining 8000 gallons from a 30000 pool, we ended up at around 90 ppm. Alkalinity is around 50 and PH is what I think is 6 or above. Can't tell with that one because the color is well below the test color for PH (it's yellow and the lowest was orange at 6.8) and this is after adding about 40 pounds of baking soda. I've added about 3 gallons of liquid chlorine to try and at least delay any further growth. If I understand the calculator right, I need about 8 gallons of 12% liquid chlroine to successfully SLAM after that, add whatever needed each day? It's weird my PH just doesn't budge no matter what I add and yes I do rinse after each use. Don't know what level of algae we're at with this color. IMG_2807.jpg
 
What are you using to test CYA?

Assuming you're testing at home with a Taylor kit, I would recommend draining and filling more until you're at 60 or below for CYA. You can try the no-drain water exchange method here Draining - Further Reading

Once you've done that, you can start your SLAM. What was your FC at when you tested the pH? High chlorine levels can interfere with the pH test. It would be really unusual to have a pH that low, but anything can happen.
 
  • Like
Reactions: Mdragger88
We went to the pool store to test it. They used a centrifuge and such. Though we recently went to the store to get a test again and they said it shot to 133 to both of our confusion. They then did a manual test and it's well into the 100 range. We're both theorizing that maybe lower temp causing the CYA to settle lower and not circulating as much as we should before testing caused the true value to be concealed. I typically grabbed water from my elbow down below the water line near the deep end.
FC 16.61 (though it seems we're well past measurable range)
TC 18.61
CC 2 ppm
PH 6.5
CH 104
TA 40
CYA 133
Phosphate 212
 
Pool store testing is notoriously bad, as you’re starting to see. It’ll be different every time you bring it, leading you to buy whatever chemicals they say. CYA is especially variable.

Get one of these Test Kits

There are identical kits on Amazon, just make sure you get a fas-dpd chlorine test and the CYA test. Then you can take control and make informed decisions.

In the meantime, use liquid bleach to add 5ppm worth for chlorine to your pool every day until the test arrives.
 
I think I'm still going to go with the drainage idea to at least reduce CYA as they did do a manual test which showed that CYA was above 100. Every other metric was pretty accurate so far from what testing I could do on my own. Though I do wonder where I should drain the water. I get the feeling draining it into the street to flow down the drain is the incorrect idea. There is what looks to be a drain next to the pool that might be to a proper sewer? IMG_2808.jpg
 
Honestly, I have half the mind to just drain and finally replace the liner as it's probably due for replacement. The only reason why we're trying to even kill the algae right now is that that every company is probably busy for the summer and we'd want to get some use out of the pool for the summer. It feels like completely replacing the water is the better idea at this point. If the first reading is high, and the second reading is also high, than doesn't it stand to reason that the concentration is just bonkers high at this point?
 
Last edited:
If the first reading is high, and the second reading is also high, than doesn't it stand to reason that the concentration is just bonkers high at this point?

There is no knowing for sure without accurate test results from one of the recommended test kits.
Test Kits Compared

And it will be impossible to perform a proper SLAM Process without one of the recommended test kits.
 
  • Like
Reactions: Mdragger88

Enjoying this content?

Support TFP with a donation.

Give Support
Ok. Something weird happened as we were draining and let it settle. It looks like all the algae settled at the bottom? I'm not sure what's going on here. It looks like it's kind of clearing up on its own. Unless that's just living algae at the bottom there. Like it looks really clear near the top. Am I just being a bit delusional or is the chlorine finally starting to work and killing stuff? I will say we kind of happened at our first drain and refill so I have no idea what to think anymore regarding this .IMG_2813.jpg
 
That’s not unusual if the jets aren’t mixing things up.
You can vac all that settled to waste to help keep it out of your filter but you must still do the
SLAM Process to eradicate what remains or it will look like that again quite quickly.
Have you gotten a kit on order? If not, do so asap & add 5ppm worth of liquid chlorine each day until it comes to prevent it from getting worse until you can properly slam with accurate data.
 
I mean, my question is was most of what was floating around just dead algae from us running the filter and kicking stuff up? It looked like a severe before things settled and it looks Dang near crystal save for the bottommost layers and even then I can kinda see the my pool equipment when I put it down there. Our FC levels are still high.

I guess my main question is that is all this settled green the dead algae we’ve probably been kicking up and our chlorine has been working at killing the algae, or am I just being hopeful and we’ll be back to ground 0 once we refill. Because my parents and I were debating whether or not to replace the vinyl if we’re most likely going back to ground 0 if we refill and we just settled on replacement before this happened
 
Its still very green - the algae is very much still alive.
Even after exchanging water you will still need to complete the
SLAM Process to be able to maintain the pool normally if that’s what you mean.
Exchanging the water will just lighten the load & make the slam less difficult.
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.