First attempt at SLAMing

[Pamlvt]

Hi, this is my first post. I’m new. I have a 24’ round, above-ground, 54” deep and a good ole’ sand filter.
We opened this year to a green pool. Having used TFP a little last year, I decided to try a SLAM. I started it yesterday.
My CYA is 40, pH 7.4, Alk 150. We have very very hard water and needed to add with the hose. I know the Alk needs to be lower, but I didn’t want to spend time lowering it (and consequently mess any more with the pH) with the algae going crazy. Using the help from “Pool Math” I’ve been adding the recommended liquid chlorine to reach 16ppm. Problem 1) it has never tested that high. I’m using the Taylor FAS-DPT.
My FC is testing between 9-11ppm. I’m adding chlorine and testing about every 4-6 hours depending on night and work hours. The CC started at 1. 8 and steadily increased over 24 hours to 2.5 and is now decreasing steadily. It was 2.0ppm 4 hours ago. I have brushed the bottom and sides 4 times. The water went from bright green yesterday to cloudy blue today so I feel like it’s working. Should I try harder to hit 16ppm? Problem 2) The test water goes clear and then will start to turn pink after sitting a few seconds. Should I continue to put drops in until it is clear for a while, or stop when it first becomes clear? Last question; once the algae is dead, could I use clarifier to speed the clearing process? I put a cup of DE in the filter tonight after backwashing and will continue doing that to help my filter be more efficient. Sorry for the long post, just wanted to provide as much info as possible. Thank-you in advance for your advice!

 

[mknauss]

Welcome to the forum!
1. If you can test and add chlorine every couple hours at the start it will go quicker. But do the best you can.
2. Once the test sample goes clear, the test is complete. Ignore the return to pink .
3. We do not recommend clarifier. It is glue and can gum up your filter media.

I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.

 

[Texas Splash]

Welcome!

 

[Pamlvt]

Thank-you! If the test is complete when the sample first goes clear, that means my FC level is much, much lower despite using the calculator’s recommendation. The chlorine I’m using is a 10% solution, but I got it at Wal-Mart because it’s the closer than a pool store. I live in a very rural area. The pool store is an hour away. Could chlorine quality be part of the problem?

 

[mknauss]

Could be but most is pretty fresh this time of year.
Look on the bottle, is there a number like 19XXX? The 19 stands for 2019, the XXX is the day of the year it was bottled. Nearly anything bottled in 2019 is still pretty good.

Did the pool have the 40 ppm CYA in it when you opened it?

 

[parisdpm]

Thank-you! If the test is complete when the sample first goes clear, that means my FC level is much, much lower despite using the calculator’s recommendation. The chlorine I’m using is a 10% solution, but I got it at Wal-Mart because it’s the closer than a pool store. I live in a very rural area. The pool store is an hour away. Could chlorine quality be part of the problem?

I've not found 10% bleach. Clorox brand says 6%, Great value said the same. I was using bleach from Rural King, until tonight, when I discovered it was 2.5%. I learned all bleach is NOT the same.

 

[Pamlvt]

I've not found 10% bleach. Clorox brand says 6%, Great value said the same. I was using bleach from Rural King, until tonight, when I discovered it was 2.5%. I learned all bleach is NOT the same.

This is pool chlorine from Wal-Mart. I started with Great Value extra strength which was 6%, but the pool chlorine there was actually a better value. Just wasn’t sure if there was a quality issue. I realize that a solution is a solution, but I don’t know if Wal-Mart’s stock is fresh and I do know that chlorine (in any strength) loses affectiveness with age. What may have started as a 10% could be 1% solution if it’s a year old. Just wondering if anyone has had the same experience.

 

[Pamlvt]

Could be but most is pretty fresh this time of year.
Look on the bottle, is there a number like 19XXX? The 19 stands for 2019, the XXX is the day of the year it was bottled. Nearly anything bottled in 2019 is still pretty good.

Did the pool have the 40 ppm CYA in it when you opened it?

Thank-you for that information, that’s what I was wondering. It’s fresh, I just looked. No, on the CYA. There was a mis-communication between my husband and I (hence the situation we are in). He thought I put closing chemicals in and I thought he did. The pool went all winter with nothing. I added fresh CYA last weekend and it tested 40 ppm on Monday. Update this am - FC 16.5ppm. CC 0.5pmm . I think the algae load was just eating it as fast as I could add it. I think I’m on the right track now.

 

[mknauss]

Great. Stay on track.

 

[Pamlvt]

More advice please . Finally almost done. Passed the OCLT last night. This am we could see the bottom of the pool for the first time, although the water is a hazy blue. At 8am the FC was 14 and CC 0.5 (SLAM level is 16). Even though we passed the OCLT I decided to bump the FC back up. AT 5pm the FC was 14 again and CC is >0.5. I say less than because the test solution never turned pink after adding the DPD reagent. There was a small amount of tan colored debris on the bottom. Should I continue SLAMming until the water is crystal clear? Or is it ok to vacuume and filter until it’s clear leaving the FC to start to go down to normal levels?

 

[Pamlvt]

More advice please . Finally almost done. Passed the OCLT last night. This am we could see the bottom of the pool for the first time, although the water is a hazy blue. At 8am the FC was 14 and CC 0.5 (SLAM level is 16). Even though we passed the OCLT I decided to bump the FC back up. AT 5pm the FC was 14 again and CC is >0.5. I say less than because the test solution never turned pink after adding the DPD reagent. There was a small amount of tan colored debris on the bottom. Should I continue SLAMming until the water is crystal clear? Or is it ok to vacuume and filter until it’s clear leaving the FC to start to go down to normal levels?

I should add that at 10pm last night (after dark) the FC was 14 and CC was 0.5. This am it was the same. I added chlorine after work yesterday (about 4pm) to bring it up to 16.

 

[Texas Splash]

Definitely keep SLAMming! Leave the OCLT until last. Since you still see debris settling, keep going. Hazy blue is better than green, but it needs to be crystal clear. Imagine a dime or quarter at the bottom of the pool. You should be able to read heads or tails. Hang in there! Brush each day and try to get everything into the filter for backwash. You're getting close.

 

[Pamlvt]

Will do! Thank-you!