Auto-cover rests on water - Achilles heel of algae management?

[crimson avenger]

My auto cover was improperly measured by my pool installer. We have been waiting since the end of last summer for the replacement.

It sags in the water when closed.

I had a complete aha moment and also realized I was such a bonehead when I thought about the pool cover! Is it possible that algae is just hanging out on the underside of my cover? The cover was installed last year before I was a perfect disciple of TFP.

I clearly can’t brush it… I don’t have scuba gear…

 

[Rocket J Squirrel]

All autocovers rest on the water surface by design. If your cover fabric is too wide, you'll see wrinkles. Some wrinkling is OK, but creases are bad because they can eventually tear and require patching. What do you mean by "sag"? Show us a pic?

As long as you maintain proper chemistry, algae won't form on the underside. Do you have evidence of algae or just worrying about it?

 

[needsajet]

Does the auto-cover park underwater by any chance? I helped out with one of those a few years ago.

Is the autocover demountable? i.e. could you take it off and lay it upside down on your driveway or lawn?

Like Rocket above, I'm also wondering if you've done the Overnight Chlorine Loss Test and know if you have an algae issue.

 

[crimson avenger]

I’ve had multiple slams over the last year and failed multiple overnight chlorine loss tests when every other source had essentially been eliminated. This is such an obvious source to me that it should really be considered at least to be answered as part of the TFP guidance.

 

[needsajet]

My experience has been that covers can contribute to algae problems. On a bubble cover, you can see the algae growing on it after storage, and sometimes on top while in use. As they get old, algae starts hiding in the bubbles that are no longer sealed, or along the edges. The cure is to do a SLAM when you first start using it, and for me, I need to keep my FC up to 10% of CYA while the cover is in use.

I wonder if you could SLAM with the cover closed, and do something to make the water turbulent underneath... maybe a submersible pump with something rigged up in PVC pipe to spray pool water on the bottom of the cover.

Do you have a picture of how your cover stores away, then partly covering the pool, and fully covering? Maybe we could come up with an idea.

Another question will always be "Are you sure your past SLAMs have been fully completed?" It's not meant to be scolding in any way; it's just reality that SLAMs can be difficult when non-pool life gets in the way!

 

[wireform]

As said before me the cover is supposed to be supported by the water beneath. I have several pools with this auto cover you mention but with much different outcome never contributing to the algae you speak of. As this has also been said before possibly the slamming is not being followed correctly. Tell us some more on the testing .....just looking at your poolmath logs I don't see anything for PH,TA,and CYA......

 

[crimson avenger]

Autocover just rests on top of the water. There’s no part that is underwater. There are a couple of creases in it but most of the slack is taken out at the very edge of the pool as it goes down to the water.

I perform full battery of tests monthly.
pH daily unless SLAM. pH has been stable at 7.5 for over a month without any acid addition.
chlorine daily.
I had 18 people last Saturday and immediately after I have noticed CCs over 0.5. There must be some sort of nascent algae problem, or my small pool just takes more time to recover after a massive pool party. Since we opened first week in April my chlorine demand has been minimal. The party put things over the edge and I tested down to a nadir of 5 FC, well within the acceptable range for a CYA of 50.

 

[needsajet]

CC after a pool party is normal. The FC removes ammonia added by people. Just part of its job. Can be all from perspiration and can be from other sources. This aspect is not related to algae, unless minimum FC levels drop too low because of doing that part of the job.

 

[crimson avenger]

CC after a pool party is normal. The FC removes ammonia added by people. Just part of its job. Can be all from perspiration and can be from other sources. This aspect is not related to algae, unless minimum FC levels drop too low because of doing that part of the job.

I get that… but I’m day 6 after our big pool party and my morning testing revealed a CC of 1. Is that normal?

 

[needsajet]

No, not after a long period of little use. Is the pool open when the sun is shining? That will help burn off CC.

 

[crimson avenger]

No, it has been closed most of the time since then. The auto cover is usually on. I usually open the cover for 15 minutes prior to testing though.

 

[needsajet]

If it were mine, I'd keep it open during the day, and see how it goes. As they say, pools need to breathe. Alternately, opening it for a couple of hours every day would do the trick.

 

[crimson avenger]

If it were mine, I'd keep it open during the day, and see how it goes. As they say, pools need to breathe. Alternately, opening it for a couple of hours every day would do the trick.

I’m going to keep it open for the next 24 hours and see what happens.