Can't seem to get a hold of the problem....

[smiller328]

I could write a book about all I've been through with the pool this spring/early summer, but will try to keep this succinct.

I've typically needed to SLAM once a season (this is my sixth season with a pool) and have usually been able to get a hold of any issue really quickly since I test daily and notice right away if something is happening. Historically, I've only needed two-three days to get OCLT to pass. Not so much this time and I have no idea why and am getting really discouraged. The pool looks amazing but something is absolutely demolishing chlorine at an alarming rate. Currently adding upwards of 2-3 gallons of 12.5% chlorine per day just to try to stay at SLAM level of 16 FC... I've been at this for over a week now, and it is not slowing down at all (losing 12+ FC PER DAY).

After reading through many other posts I've taken apart pool lights as best I can, have no ladders or main drain to clean, so suspect it may be something in the skimmer (but perhaps this is a red herring so please provide other suggestions if you have any).

Why I fear it is the skimmer and have no idea what to do:

(1) In the attached pictures you will see some "scuzz" in the skimmer that is greasy/oily - I convinced myself that it was sunscreen but am starting to second guess that position. Thoughts? It definitely seems related to pool usage as there is more after people use the pool and hardly any if the pool is not used. Regardless I've been brushing/wiping it down as often as I can.​

(2) If this is some sort of algae/organic you may notice in the picture the skimmers have cracked over the years (probably due to winter freezing/concrete settling?) - how will I EVER get inside those cracks to properly brush/clean them? If this is the problem, is this why it won't "go away"?​

(3) The installer put too much caulking around the skimmer mouth plate so it is also impossible to fully clean (the caulk also has some black spots above the water line in it - is that algae?).​

Current readings (pool is sparkling, no one would ever guess something isn't right - attached picture has pump on high and was dark and windy but you can clearly see the bottom of the deep-end from ~60 feet away):

FC 16.5​

CC 0.5​

pH 7.6​

TA 100​

CH 260​

CYA 40 (between 30 and 40, so round up)​

Salt 3400​

Temp 86​

​

Any suggestions/help would be greatly (greatly!) appreciated.

Cheers,
Steve

 

[Mdragger88]

Spray some 50/50 bleach/water in there & go at it with a brush after it sits a while. Same with the caulk area.
Have u checked the weir door foam? Like pulled it out & checked the back?
Give any eyeballs a good scrub as well.
Aside from that, are there any un used/abandoned ports/lines?
What kind of vacuum do u have? Check it & the hoses etc.

 

[smiller328]

I have not checked the back of the weir door (i.e. never have removed the foam), will do so when I get home later today. No unused ports/lines. I just have a simple triangular vacuum head and hose and turn the pump on high to vacuum.

 

[Mdragger88]

Here’s the most recent one

Algae Behind Weir Door

Forgive me TP'ers for I have sinned. It's been since my last confession. I've seen the advice often to check the foam on the weir door when having a tough SLAM. I dismissed this thinking it doesn't apply to me bc I imagined some foam stuff at the edge of the door, sort of like around a...

www.troublefreepool.com

 

[jeffchap]

Are you brushing? My opening SLAM lasted longer than normal this year and I finally discovered I had algae growing on the pool walls. I'd never experienced that before and consequently had never needed to brush before. Once I started, the SLAM wrapped up quickly.

 

[Mdragger88]

Definitely gotta brush those biofilms!

 

[smiller328]

Thank you so much gang! Mdragger88 - you nailed it! See attached. I don't know why in my reading I hadn't come across the hidden weir algae (I shall call it HWA - it sounds as nasty as it is). Attached you will see how nasty it was.

jeffchap - I agree, I have a fiberglass pool and haven't had to brush much in the past during SLAMS. However, after what I found, I have re-doubled my efforts on that front.

Finally, I also re-opened the filter and wasn't enamored with what was going on in there so cleaned it up again.

Hope I will finally get a hold of this thing! Will keep you posted.

Cheers.

 

[Mdragger88]

Death to algae!

 

[smiller328]

Some but not much progress... Scrubbed everything (eyeballs, weir door, skimmers, pool walls and floor). I'm starting to fear it's the underside of the autocover (no idea how to scrub that) or in the pipes underground (also not sure what to do).

Any other suggestions?

 

[Mdragger88]

Here’s some info about cleaning the cover

Pool Covers - Further Reading

www.troublefreepool.com

 

[smiller328]

Thanks again Mdragger88. I read through that but didn't see anything about how to clean the underside of an automatic pool cover (in case that's where the algae is hiding). Interestingly, I have a free form pool with an automatic cover, which the article says isn't possible.

 

[Mdragger88]

It basically says if u have algae to clean it with a little bleach mix & rinse well - it also says that since when it rolls up the top comes into contact with the bottom so anything you use on the top will touch the bottom. If u have the ability to close the cover partially & get in the pool with a light to inspect it you should.
It doesn’t look like your cover really comes in contact with the pool water so it may not be the culprit but a good cleaning might be a good idea anyway.
I think the article was mostly referring to inset auto covers which aren’t possible w/ free form shapes. I really like the fact that u have the rectangular cover on the free form pool. Do the tracks get in the way?

 

[smiller328]

Great idea, I don't know why I didn't think to roll up the cover with a little bit of chlorine/water on it. I'll try that (1:9 chlorox).

As for if the rails get in the way on a free form, yes, but nothing that's too annoying/problematic. The rails themselves are fine, there's a "stopper" on each rail at the far end from where it rolls up that could be pretty bad toe stub, but in six years, hasn't happened yet (they're pretty apparent yet not huge). I can post a picture.