1 month of SLAM and no OCLT pass

[2WeeksNotice]

• 4/22 start to open. Water temp 58F. Lotta worms in the sweeper this year. Very cloudy blueish water but not green—could not even see the sweeper when it was on the bottom. Used Polyquat at close in Oct (with relatively high FC if I remember correctly).
• 4/22 to 5/8 CYA 20; SLAM at 10 FC. Started at 7.2 pH. Slow progress but eventually got clear water, but could never get OCLT to pass. Usually, it was a 1-2 FC loss and 1 CC.
• 5/9-5/21 Temps & sun starting to be more consistent, so decided to bring up CYA to 50 and continued to SLAM at 20 FC. Water still clear and still failing OCLT at about the same amount as above. Got tired of buying LC and lax on OCLT rigor so supplemented with SWCG during the day; some of this was to make sure everything was working OK for the season. During this time, I also bought Taylor K1106 Phosphate test kit; tested at 4000ppb. Was wondering if this could be contributing to the FC loss problem. But I had added Jack’s purple stuff late last summer, so this could affect the phos level (?). I did not treat for phosphates after the 4000ppb…don’t want to deal with that unless I have to.

Water is still crystal clear and swimmable, but still can’t get OCLT to pass. Lots of cottonwood seeds, pollen and oak catkins as we live near big timber. These gets swept daily and I have a knee-high sock over the skimmer, cleaned daily as well.

Have removed and cleaned every piece of white plastic in the pool and no signs of algae. Also cleaned and sprayed the auto cover well with chlorine/water mix, as that gets pretty gunky. Underside of autocover is clean.

Had a couple air leaks that just got fixed Saturday. One was the 2” PVC between filter and heater. The other were Jandy swim jet lids and main pump lid needed Teflon lube or a new o-ring. No leaks now.

Water tests last night: FC 19.5, CC 1, CH 400, TA 70, CYA 50, Salt 3800. pH was 7.2 when I started this a month ago.

Questions: I know passing OCLT should be achievable, but wondering if the spring air stuff is a hindrance to that? I don’t think the air leaks would contribute to FC loss? I would like to raise the CYA to 70-80 in the next few weeks before it gets hot, but then SLAM gets more inefficient. Any advice? One month of SLAM with no change in OCLT seems odd.
Thanks for any help!

 

[PoolStored]

I know passing OCLT should be achievable, but wondering if the spring air stuff is a hindrance to that?

No.

I don’t think the air leaks would contribute to FC loss?

No

I would like to raise the CYA to 70-80 in the next few weeks before it gets hot, but then SLAM gets more inefficient. Any advice? One month of SLAM with no change in OCLT seems odd.

Let's hold off just a bit.

What are these round covers? Have you removed them and scrubbed behind?


Do you have lights? What kind?
Do you have a main drain?
Have you removed the weir doors and checked for algae in the foam?
Have you scrubbed the skimmer and skimmer mouth (with weir doors removed?
Do you have an autofill? Scrubbed it?

 

[proavia]

The FC of 19.5 - was this tested at least 15 minutes after your last chlorine addition?
What was the FC and CC this morning?

Is water crystal clear with no signs of algae (dead or alive)?
Have you checked behind the pool lights and all sides of the skimmer weir door?
Have you left the auto cover open the entire time?

 

[2WeeksNotice]

Lots to reply to...thank you @PoolStored and @proavia !
1. Round covers are swim jet intake and air lines. Yes, removed and scrubbed with Magic eraser. No signs of algae. Just light iron staining.
2. Lights are 4 small LED's (1 to 1.5 inch dia). You can see it in the pic by the white covers. Not sure I can remove these lights or do I need to?
3. Yes, have a main drain. Similar white covers as swim jets. Yes removed and scrubbed them. no signs of algae.
4. Removed weir foam last year when it held mold and drove me nuts for 3-4 weeks. Yes, scrubbed the door and skimmer and mouth with Magic Eraser. There is some minor accumulation of sticky black junk on the skimmer box every 3 days or so. It wipes off easily with magic eraser.
5. No autofill. and have not needed to add any water yet.
6. Yes, FC of 19.5 was well after any LC, but SWCG had likely been running. ~30% from 8AM to 8PM.
7. Did not do FC and CC this AM...very early work day.
8. Yes, water has been crystal clear with no algae dust for at least 10 days, maybe more.
9. Auto cover is not open all the time, but has been open plenty. Trying to keep out all the spring airborne stuff. It's nearly always covered at night.

Should also mention that I have 2 sets of cartridges. First set stayed in until water was clear, then I put in the 2nd set while rinsing the first. Left 2nd set in and rinsed the bugs and cottonwood stuff out on Saturday when I was fixing plumbing leak. While the filter housing was empty, I scrubbed it with strong chlorinated water, as I recalled at opening there was a reddish/white stuff on the inside of the lid. I scrubbed it away at opening, but did it again Saturday just to make sure.
4 of the filters are stored all winter in PVC tubes in the shed. They should have been fully dried at storage time, but any chance the pipes don't allow airflow and let mold grow? Even so, seems like that much SLAM time should kill it?

 

[PoolStored]

Yes removed and scrubbed them

The covers or the main drain itself?

 

[2WeeksNotice]

The covers or the main drain itself?

covers. sorry, maybe need to define main drain....my PB called it the main drain but it really is the deep end supply lines to the pump. So I guess it's not the main drain. Just that he labeled the pipe "MD"....so that's stuck in my head. I have no way to drain the pool other than pump it out. clear enough?

 

[PoolStored]

It is a main drain. That is why the PB labeled it MD.

Need to get down there and remove the cover and scrub cover and under main drain cover in and around the drain. It will likely have two screws and may take a couple dives. You can use a dumbell to help you stay down there (do not use a weight tied to your body). You need to turn the pump off when you do it.

Post a pic of the MD.

Also can't tell from pics...do you have ladder?

 

[Mdragger88]

They’ve got you well covered on the hidden algae front.
For the persistent cc’s-
The cover will trap cc’s overnight so try leaving that open for your next oclt.
Also, if you haven’t lately, clean your test cylinder with alcohol then rinse it well. & your stir bar too if you use a magnetic stirrer.

 

[2WeeksNotice]

@PoolStored -- 2 main drain covers have been removed and scrubbed in & around (4 screws per cover...yes, it takes a couple dives). Pic tomorrow. No ladder, just steps.
@Mdragger88 -- storming tonight, but will leave cover open tomorrow night and see if that helps. I have cleaned the test cyl with alcohol, but not the stir bar. Will get that done.
Thanks both.

 

[proavia]

For the Overnight Chlorine Loss Test, leave the cover open all night.
SWG off
Test FC 15-30 minutes after last chlorine add and after sunset.
Before sunrise test FC and CC
Both tests need to be mixed well - pump onfor 15-30 minutes prior.
Report your results here.

 

[2WeeksNotice]

Post a pic of the MD.

 

[2WeeksNotice]

For the Overnight Chlorine Loss Test, leave the cover open all night.
SWG off
Test FC 15-30 minutes after last chlorine add and after sunset.
Before sunrise test FC and CC
Both tests need to be mixed well - pump onfor 15-30 minutes prior.
Report your results here.

followed all the above to a T. Cleaned all testing stuff with alcohol.
5/22 9PM - 12.5 FC; 0.5 CC
5/23 5AM - 11.5 FC; 1.0 CC; re-test to validate 11.0 FC; 1.0 CC (almost 0.5, if that counts)
Note FC values are lower than the 19.5 listed earlier, as I stopped adding any chlorine Monday until I got this resolved with the group here.

 

[Texas Splash]

Geez, you are so close. With everything you have done, I can't help but wonder if that cover has some junk under it. We've seen pool covers responsible for trapping mold and algae. Hang tight and give the others time to have their morning java and catch-up to your OCLT results. They've been your primary coaches through all of this and will have some input for sure.

 

[proavia]

From the time you reported FC 19.5 a few days ago until this morning, how many hours was the cover closed or partially closed?

I think Pat @Texas Splash is on to something - the cover.....

I'd leave the cover open and go back to SLAM Process FC levels now.
Do another Overnight Chlorine Loss Test tonight and report back.

If you pass the OCLT, go back to closing the cover and do another OCLT to see if anything changes.

You are so close. Would hate to see you end the SLAM only to have the issue reappear. You need to eliminate the cover as the issue or clean BOTH sides of the cover, cover tracks, vault, ropes, etc.

 

[Bperry]

I think Pat @Texas Splash is on to something - the cover.....

I'd leave the cover open and go back to SLAM Process FC levels now.
Do another Overnight Chlorine Loss Test tonight and report back.

If you pass the OCLT, go back to closing the cover and do another OCLT to see if anything changes.

A pool cover is often a common detail in SLAM that seems to take forever.

 

[2WeeksNotice]

I'd leave the cover open and go back to SLAM Process FC levels now.
Do another Overnight Chlorine Loss Test tonight and report back.

If you pass the OCLT, go back to closing the cover and do another OCLT to see if anything changes.

Yes, it does seem so close! Will give this a whirl again with cover open tonight. I have been under the cover already last Saturday and it looks great. But will check vault (again), guides, cables etc. Have not cleaned the topside of the cover since April. Will hit that again when I can. Heavy rain predicted tomorrow during the day...other posts look like SLAM during rain is business as usual, but just check FC more often for dilution? Thank you!!

 

[proavia]

Yes, it does seem so close! Will give this a whirl again with cover open tonight. I have been under the cover already last Saturday and it looks great. But will check vault (again), guides, cables etc. Have not cleaned the topside of the cover since April. Will hit that again when I can. Heavy rain predicted tomorrow during the day...other posts look like SLAM during rain is business as usual, but just check FC more often for dilution? Thank you!!

The top side of the cover and the underside of the cover touch each other when the cover is retracted.
While you cleaned the underside, it became contaminated by the top side when you retracted the cover.
Suggest you clean BOTH sides of the cover again.

 

[2WeeksNotice]

Good morning all...cover open all day yesterday and overnight. SWCG ran during the day and then I added about 1.5 gal LC at 8PM. Circulated the swim jets ~ 1 hr after adding LC. Main pump ran on low all night. OCLT results:
5/23 9PM FC 21.5, CC 1.5, CYA 50

5/24 5AM
Test 1 - FC 20.5, CC 2.0 (2.0 was surprising, so ran another)
Test 2 - FC 21.0, CC 1.0 but almost 0.5 (in light of the above CC 2.0, this was very confounding; also, powder vial was near empty and powder was turning black, also the dropper was very near empty, so got new of each out. These all are from TFTestKits this year)
Got a new test sample from the pool. Same place, near the skimmer, 1' deep, rinse out bottle with pool water first.
Test 3 - FC 17.5, CC 1.0 (not moving in the right direction)
Test 4 - FC 17.0, CC 1.0 (stumped)

New powder and dropper shouldn't affect FC results that much?? I was very happy with and confident in the repeatability of the tools and my methods up until now...but if the results or materials are that variable, then passing the OCLT will only be by fluke. And if the 2nd set of powder and drops are correct at FC 17, then I was never really at FC 20 SLAM for CYA 50? How do I get confidence back in the test materials from one batch to the next? Any help?

 

[PoolStored]

Have you cleaned your test vial? With all the testing your are doing they get dirty. I clean regularly. Do so with rubbing alcohol.

 

[2WeeksNotice]

Yes, sample bottle, test cylinder, and mag stirrer all cleaned yesterday with alcohol.