First Pool Opening - SLAM?

[ayopyo]

Hello,

This website has been great and I've learned a ton so far! I've read through the Pool School articles and tons of forum threads, however have a question as to whether I should SLAM or not. I have a 28 ft' round AGP with a cartridge filter that was just installed at the end of season in 2022. I didn't know anything about chemicals and put in whatever the pool store provided in their closing kit. I opened the pool a few days ago with the warm weather in Wisconsin and did my first chemical test, using the TF-Pro with Smart Stir kit.

4/17 Test Results (afternoon):
FC 0
CC Missed to test
CYA 0
CH 100
TA 80
PH 7.8

Based on the test results, I added the recommended amount of chemicals per PoolMath: 57oz 12.5 liquid chlorine, 7lbs dry stabilizer via sock method, and 9oz 31.45 muriatic acid.

After adding the chemicals, I was reading some more on the forums and read that if the FC is 0, you should SLAM. Also, I read that if the CYA is also 0, that you should get FC under control first via the SLAM process, before adding stabilizer to increase the CYA, in case their is a potential ammonia issue? However, I had already added stabilizer. I tested again this morning.

4/18 Test Results (morning):
FC 2
CC 0.5
CYA 30
CH 150
TA 80
PH 7.2

Based on the test results this morning, I'm not sure if I should SLAM or continue to test daily and add the recommended chemicals per PoolMath? The pool is clear, I don't see any algea or cloudiness. Appreciate your input!

 

[reggiehammond]

An overnight chlorine loss test (OCLT) can confirm if you need to SLAM. But it's probably a pretty safe bet to go ahead and do it. With a CYA of 30, it's a perfect time to do it, won't cost a lot, and should go quickly.

I wouldn't worry much about ammonia - if you had it, you'd register no FC, even minutes after adding.

 

[ayopyo]

Thank you that is very helpful. I will go ahead with the SLAM. Is there any estimate of how long it will take at my levels?

Also, regarding brushing - I haven’t done that yet. Do I need to brush the floor or just walls / steps? I have a Dolphin Explorer E70 that I will run toe vacuum daily.

 

[ayopyo]

I added 1 gallon and 2 quarts of 12.5 liquid chlorine an hour ago to bring up to 12 FC, based on 30 CYA. Just re-tested, 1 hour post adding, and was at 11.5 FC, 0.5 CC and 30 CYA. Will test again in about 1.5 hours.

 

[mknauss]

An overnight chlorine loss test (OCLT) can confirm if you need to SLAM.

Do the above tonight.
No need to test CYA. It does not change unless you exchange a large amount of pool water for fresh water. Test CYA monthly or after any large changes.