Mis-SLAM ?

[Micans Aqua]

Mea Culpa... Mea Culpa... Mea Culpa...

Hi everyone!
New mbr here.
Just moved into a home here in Austin with a small fiberglass pool. The move-in was delayed for almost 9 months... the new house was distant, and I was too undisciplined to visit regularly and keep the pool properly. It looked exactly like the pool on the SLAM page. Under mucho pressure to recover the pool asap. Totally mentally and physically exhausted, still unpacking and in-laws arriving Saturday. Scanned (poorly) the SLAM page and missed a couple of major points... "balance the pH before starting," "take it slow, no shortcuts."... You can guess what follows...
Thursday night I A-bombed the pool (BBB). No, really, full-on A-bombed. [~6lbs of leftover Cal Hypo 68% and 363 fl oz Clorox 8.25%] Dark green to light pea-green, slightly gray/cloudy... overnight.
Friday, I started testing, first with Leslie's 6 measure strip... and used Pool Pal app
1300 hrs: FC zero TCl zero Alk 120 TH 800 Cya 40
1730 hrs: dropped another 242 fl oz Clorox and 12 lbs Borax
2100 hrs: (finally broke open the TF-100) FC 11 CC 3.0 TC 14 CH 400 Alk 200 Cya 90

Saturday
1045 hrs: FC .75 (interpolation) CC 1.5 TC 2.25 CH 525 Alk 160 Cya 75

I don't yet feel confident in this statement... it seems I'm headed in the correct direction? I hope I haven't damaged the pool/filter/pump by beginning without fully understanding and following the instructions. Today's plan is to brush, brush, brush... allow to run on "Fast Clean" (2750 rpm) a couple of hours, disassemble and clean filter, return to "Fast Clean" and brush, brush, brush and dose.

I would be grateful for any feedback, guidance and especially recommendations for next chem dosage amounts...

Thank you all ! :-D

 

[jblizzle]

Welcome to TFP!!!

Given the high CC numbers you were seeing and the fact that the FC is still so low, something was consuming the FC very quickly, so not likely any damage done.

Forget the strips and just use the TF-100.

We need to figure out your CYA so you know what FC level to be trying to maintain ... it is impossible for it to go from 40 to 90 to 75, must be testing error.

Review the Extended Test Instructions ... lighting is very important for the CYA test.

 

[Micans Aqua]

In-laws arrived early. Wasn't able to do anything to the pool. No brushing, no cleaning of the filter. (The water is getting less green and slightly less cloudy.
Test Results
Saturday
1815 hrs: FC .5, CC 1.0, TC 1.5, CH 550, Alk 150, Cya 80 (reviewed ETI and Taylor photos, ran test 3X from same bottle, in 3 different well sunlit locations, same results each time.)

Do I correctly interpret the Chlorine/Cya chart that at Cya 80 I want to take FC to 31?

 

[jblizzle]

That is correct for the SLAM process. You need to keep the FC that high until you pass the 3 criteria to stop.

 

[Richard320]

Yes, 31 is correct.

 

[Micans Aqua]

I think I read it's not terribly reliable during the SLAM (especially since I didn't balance prior to starting)... for comparison purposes, pH is ~7.6

To get to FC 31 Pool Pal says add 713 fl oz of bleach. Sound about right?

 

[jblizzle]

You need to lower the pH before raising the FC above 10ppm. That is the first step of the SLAM.

 

[Micans Aqua]

Noted in beginning thread... guilty as charged... I began SLAM before leveling pH.
Do I need to let it stabilize a day or two, and adjust pH before proceeding?

 

[Richard320]

Noted in beginning thread... guilty as charged... I began SLAM before leveling pH.
Do I need to let it stabilize a day or two, and adjust pH before proceeding?

You added Borax early on and ended up at 7.6 pH? Is that correct?

If you haven't raised FC yet after taking those last readings, adjust pH to 7.2. Then add bleach 30 minutes later.
If you've already dumped the bleach, my advice is to keep SLAMming. You've got too much bleach invested now to ease off and let the algae recover. It would mean all those jugs died in vain.

 

[jblizzle]

What is your current FC? If it ever drops below 10, fix the pH.

 

[Micans Aqua]

Several hours ago FC was .5, so

Lowered pH to 7.2

Then 30 minutes later added 6 btls of Clorox to bring FC to 31 per 80 Chlorine/Cya chart

I'll test before bed and again in the morning and post results tomorrow.

Thanks Richard & JB!

 

[Micans Aqua]

Update

The first reading below was 2-3 hours after Clorox add.

Saturday
2330 hrs. pH 7.8, FC 35, CC 3.5, TC 38.5, CH 550, Alk 180, Cya 90

Sunday

1515 hrs. pH 7.4, FC 15, CC 2.0, TC 17, CH 600, TA 150, Cya 100


Ok, what I notice is:
1. pH is slightly higher - should I adjust it back to 7.2 before adding bleach?

2. at 100 CYA is increasing and I think I want to lower it closer to 50-40, this is important
a) to lower CYA I need to drain some water and replace - should I do this now, or just continue SLAM and reduce later?

3. OCLT was 20, still too much - continue SLAM
a) CL/CYA chart at 100 CYA to shock to 39 - add 561 fl oz bleach

4. CH appears to have increased - not terribly significant at the moment but eventually will want to lower a little?
a) to lower CH I need to drain some water and replace... it can/will be adjusted when CYA is adjusted


Am I reasoning correctly?


and, always, thank you for your coaching!

 

[Richard320]

No. The pH test is unreliable above 10 FC. Ignore everything but FC & CC during the SLAM.

How did CYA rise? Did you recently add CYA and it just hasn't dissolved completely? If it is 100 or over, you'll want to drain a bunch and refill. And if you're draining water, why waste chemicals treating it just to dump them out again?

 

[Micans Aqua]

Haven't ever added CYA.
It's probably beginner operator error conducting the test.
Last checks were outside in full sunlight. Today's check was done inside... raining cats n dogs outside and cloudy.
I'll try another reading tomorrow and get back to you.

Thanks Richard!