Stumped - Never ending SLAM, Dropping CYA?

beemer

0
Mar 29, 2016
50
Spring, Texas
Long story short - I procrastinated too long and let the FC in the pool hit .5. Water was still blue, just a TINY bit cloudy. Started the SLAM. Been at it for 6 days. I have slammed twice before (once with VISIBLE algae) and it's never taken more than 2-3 days to successfully finish the SLAM. I am now 6 days in and while I passed an OCLT test twice early on my CC is keeping steady between .5 and 1. In previous experience it's gone to 0 in a day or so of starting a SLAM. I've been brushing religiously (2x day) and monitoring chlorine every 2 hours during sunlight. Filter and cleaner are running 24x7. I've kept the FC levels above shock (well above as I assumed my CYA would still be 50, but it's dropped down to 30 since the first weekend in May - though we've done nothing that should have caused it, and no significant rain?)

Here's a full set of numbers from 10am:
FC: 22
CC: 1
PH 7.8 (pre SLAM) though prior to the SLAM it's been rising quickly for the last couple of weeks.
TA - 90 (was 80 pre SLAM?)
CH: 250
CYA: 30 (was 40 pre-SLAM, and 50 1st week of May??)

I did throw in 2 1lb bags of 73% cal-hypo shock that I had laying around when I ran out of bleach, and my local store hadn't restocked from my last bleach raid.

I rechecked both the TA and CYA twice with different water samples just to be sure... I wrote off the initial drop off in CYA due to different light conditions (cloudy vs. full sun), subjectivity of the dot test, etc. But there's no doubt about it, it's definately 30 today. No mistake the dot's visible at 40.

The only other item of note is that I had a full filter clean by the pool builder at the beginning of the week as I was having filter pressure issues (air in the filter basket) with no obvious clues as to why. Pressure was at 22. But the filter was overdue for a clean, and a nasty grey color. After the full clean pressure dropped to 18. It's been steady at 19 since the beginning of the SLAM.

Should I backwash to clear the filter anyway? As the pressure hasn't come it it didn't seem like there was any reason to?

Anything else I should be doing? Besides being patient. :) I tried that for the first 5 days.
 
Re: Stumped - Never ending SLAM, Dropping CYA?

And I think we've finally found the source of the problem! Halaluijah! Found a nasty light brown ring in the top inch below the waterline of both of the skimmers and behind the doors. YUCK! Brushed the snot out of it and poured some bleach directly into the skimmer well (with the filter off for about 20 minutes) to theoretically help it along, or at least make me feel better anyway...

We've had strong storms and deluging downpours all afternoon. At least it's kept the bleach from burning off quite as quickly, or maybe there's hope afterall??? Only lost 1.5ppm over the 3 hours of this last storm and CC is down to .5.
 
Re: Stumped - Never ending SLAM, Dropping CYA?

That almost sounds like a scum ring in the skimmers. I get that as well from time to time. Some good old elbow grease, Magic Eraser, or as you did some bleach gets it done. But I'm not so sure that's your issue. I hope so, but if it's a scum line that's never caused me to SLAM. Today's storms should help your effort as far as bleach goes. Speaking of bleach, if your pool store is out, do you have an HEB nearby? I use their regular Bravo bleach (8.25%) @ $2.94 a gallon. Just a thought. Stay off the cal-hypo if you can as your CH will probably climb once you start refilling from evaporation.

The grey junk in the DE sounds like dead algae. Watch the pressure gauge. Next time you shut the system off, make sure the gauge falls to zero. If not, you know the gauge is bad. Also after your next backwash, make notes of the clean/baseline pressure and backwash once it increase by about 25%. It doesn't take much.
 
Re: Stumped - Never ending SLAM, Dropping CYA?

That almost sounds like a scum ring in the skimmers. I get that as well from time to time. Some good old elbow grease, Magic Eraser, or as you did some bleach gets it done. But I'm not so sure that's your issue. I hope so, but if it's a scum line that's never caused me to SLAM. Today's storms should help your effort as far as bleach goes. Speaking of bleach, if your pool store is out, do you have an HEB nearby? I use their regular Bravo bleach (8.25%) @ $2.94 a gallon. Just a thought. Stay off the cal-hypo if you can as your CH will probably climb once you start refilling from evaporation.

The grey junk in the DE sounds like dead algae. Watch the pressure gauge. Next time you shut the system off, make sure the gauge falls to zero. If not, you know the gauge is bad. Also after your next backwash, make notes of the clean/baseline pressure and backwash once it increase by about 25%. It doesn't take much.

It may have just been scum, as the scrub and soak don't seem to have made much a difference. Still seeing a FC loss of 8ppm+ through the cloudy and rainy day today.

HEB is where I buy my bleach. It's actually $2.64 here. :) Pool stores were already closed, and Walmart was further than I wanted to drive.

As for the grey stuff the guy from the pool company thought it was just excess DE from a long overdue filter clean. Let's hope he's right. The pressure gauge does drop to 0 when the pump is turned off. And it increases when I run the filter at a higher load, or run the SPA. So seems like the gauge is okay. I may backwash tomorrow just because I am all out of other ideas at the moment.

Still brushing. And still adding bleach...
 
Re: Stumped - Never ending SLAM, Dropping CYA?

FC 14
CC 1
PH7.6 (taken at FC = 9 3 days ago right before I shot it back up to 12 again...)
TA 70
CH 250
CYA 30
Filter pressure steady at 16. Running 24 hours a day on HIGH.

OCLT test from last night:
@ 8:45pm FC = 28 drops = 14
@ 5:45 am FC = 28 drops = 14 CC = 1.

CC ALWAYS equals 1.
Water is crystal clear.
Brushed with a vinyl brush. Brushed with a vinyl/metal brush. Brushed with a metal brush. Hand scrubbed all of the rock wall line as it's got lots of nooks and crannies prone to growing algae when the chlorine is too low.
Been slamming for 10+ days. Passed OCLT MULTIPLE times. Cannot get the CC down to .5 or less.

No ladders. 1 umbrella hole - brushed, brushed, and brushed about a million times. Seriously I've lost count. 20+?

Scrubbed the skimmers. Repeatedly. And the spa spill overs.

Took apart the see through shut off valve thing and scrubbed the green stuff on the metal there.

Had the pool company do a full filter clean 3 weeks ago. Backwashed once since then. When pressure went to 17 for lack of a better idea...

WHAT IS THIS!?!?!?!? And better yet HOW DO I GET RID OF IT!?!?!?!? Seriously desperate. And frustrated. And in tears. And ready to fill it in with dirt or worse, go to the pool store and do whatever they tell me to.

Please, please please. HELP.
 
As long as your water is CRYSTAL clear and you are passing multiple OCLT, I would suggest letting your FC drop to 20% of CYA and run another OCLT and see what your CC is in the morning. Sometimes elevated FC in relation to the CYA can make passing certain elements of the SLAM difficult.

Hope that helps.
 
No surprise CC's are still 1 - 1.5. Still dropping 8+ppm FC during the day. Resumed SLAM. Pulled the lights. And the spa jets. They all look clear and clean but plan to leave them out until this is over... if it ever is. Been 4 more days still no change. Losing 0-1ppm overnight (except last night but we had a massive storm that dumped tons of leaves and some furniture in the pool).

The only thing left in the pool is the filter returns. Is there a way to pull those apart? And we have an autofill. Opened it up and scrubbed around as well as I could, but no signs of anything growing in there.

Water is still clear, but maybe a little dull? Not cloudy, just not super sparkly?

Still stumped. And frustrated.

ETA: Also checked all the expiration dates and replaced the reagents. Officially expired in May of 2018, so just now... Tested with both sets of reagents - same results....

FC: 14
CC: 1.0

Won't get back to the pool until 4pm today. FC should be well below 10 by then so I will re-run PH, etc. and update with full results.
 

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So if my math is correct from post #1, you have been at this for 3 weeks, with one very short break a couple days ago right? Did you do an OCLT last night? I could see why FC would drop quickly during the day with a CYA of only 30. 30 is good for SLAM bleach requirements, but not so great for our TX heat right now. If you're still SLAM'ing, I would take that opportunity of the low FC to adjust your pH down to about 7.2.
 
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