operating pool with mesh cover on it until closing

CHOpool

Active member
Jan 7, 2012
26
My pool will not be used any more this season but the pool water is still 75 degrees. We know we should not close the pool until water temp is 60 degrees. We have trees all around our pool that are already starting to drop leaves and I know it will be a constant battle with them from here on out. My question is would be okay to put our Merlin Smartmesh Cover on the pool now while still operating our SWG (so I don't have to battle the leaves everyday) and then close the pool once the water temp hits 60 OR is it better for some reason? to wait until I close the pool at 60 to put on the cover? Thanks.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
8,728
Northern NJ
Since you don’t have a signature with details of your pool we don’t know what type of pool we are dealing with.

My concern would be how you monitor your pH with the cover on and pump and SWG running. And you are assuming the SWG doesn’t have any problems. I am not sure what you really intend to do.
 

CHOpool

Active member
Jan 7, 2012
26
Hi Allen -
Pool is an IG vinyl 17,200 gal. After slamming in the spring and using TFPC/BBB my water has been absolutely perfect all summer. I use the K-2006 kit for testing. My thought was I would get the water for testing out of the skimmer for the next 6 to 8 weeks until pool temp drops below 60 and I close it.

My goal is to stop fishing leaves out of the pool and vacuuming. We get so many leaves so fast they often clog the skimmer before I can get to it. My concern is am I missing something here that would cause harm or be bad to do.... ie: would it have ill effects on the mesh cover or something else ?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
8,728
Northern NJ
I think you may be ok if you have a way to test the water and add chemicals as needed. You can’t add MA through the skimmer.

You need to keep FC high so you don’t get algae on the bottom of your cover. The cover/water interface can be an algae breeding ground if it gets hot.

Pools do need to breath to get rid of CCs. Having the water chlorinated and covered will give you a buildup of CCs that you will probably smell after a while.
 

CHOpool

Active member
Jan 7, 2012
26
Thanks - I never thought about the cover/water interface potential for algae - appreciate the advice.
 
Our pool season was cut short last year by an unbelievably rainy September and October (lots of lightening and the types of storms that meant flooding all over). We are surrounded by trees and put our leaf cover on pretty much for the duration. Our SWCG generator and pump ran on schedule except for the occasional power outage. I’m not sure our temperature dropped below 60 till November. We drew water from the skimmer or loosened a corner of the net if we expected to be adding chemicals. We never added chemicals to the skimmer itself.

We actually don’t close our pool at all in winter because we might get the occasional freeze, but it’s only a matter of hours usually. We use the mesh cover all fall, winter, and early spring until our live oaks are done dropping leaves and catkins. Our mesh isn’t particularly thick, and we never noticed a buildup of CCs from having it covered. I’m sure different brands are different thicknesses.

Our net also does not usually touch our water (torrential rains excepted) because it’s put up over a safety net. We’ve not seen algae grow on it, but our pool remains open, properly circulating and chlorinated underneath. It is a big help to keep from having to empty the skimmers constantly in the fall.
 

CHOpool

Active member
Jan 7, 2012
26
Thanks for the information - sounds like you are doing exactly what I am planning to do until my water temp drops below the 60 degree threshold and I close my pool for the winter.
 

bmoreswim

Mod Squad
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Platinum Supporter
LifeTime Supporter
Jul 16, 2012
5,306
Central MD
If your mesh cover is properly tight, it will probably not be touching the water. But if it is, the water will get warmer there from the sun and be prone to algae. (That's why I think my neighbor's pool is always green come spring, because his cover rests on the water and gets superheated in spring.) I think it's a good solution if your cover will stay above the water. I think my Merlin Smartmesh cover would stay above the water as it's pretty flat when installed. I have an autocover and essentially do the same thing. I keep it closed except when the dogs are swimming in October while the leaves come down and then retract, close and install winter cover. I don't think you'll have any CC issue with a mesh cover. Air passes through it when the wind blows, and under it when it really blows.
 

NYAVGUY

Active member
Jul 14, 2014
43
New York
I do this as well. Out mesh cover on when season is over for swimming so I don't need to vacuum leaves out. I test weekly through skimmer and release area near return if I need to add acid or liquid chlorine.

Agreed that keeping cover off water is important. I have one return pointed up and one down for circulation. I lower run time and swg level to compensate for less chlorine loss through mesh.
 
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Newdude

Well-known member
Jun 16, 2019
704
NY
If you cant easily get water from the covered skimmer, you can get it from the pump basket. A couple of seasons i had the equiptment running early and it took a while for the free time and weather to cooperate. Another couple of times i covered the pool at closing and didnt get around to dismantling the equiptment for the same reasoons. It ran great covered both ways. FC loss was at a minimum and PH was pretty stable too with much less sunlight.
 

NYAVGUY

Active member
Jul 14, 2014
43
New York
I was going to start this discussion anyway, but I have been doing this for the past couple of years with minimal algea growth. I have a Mesh safety cover that is no solid and allows water and some sunlight through.

For closing
  • I balance all the chemicals per TFP reccomendations with the addition of ensuring there are no phosphates in the water (I use Natural Chemistry products). I also put in a bottle of Polyquat algea control and follow directions on bottle for winterization.
  • usually put the cover on late September early October, but I do not winterize.
  • I change my schedule to run the pump about 3-hours per day with minimal chlorination and check it once a week through skimmer.
  • Once water temperature is 58 degrees I winterize the plumbing and equipment. I don't do a full SLAM, but I shock the pool (I release cover near return) to ensure there is no CC and usually have the FC level between 10-15 when turning off the equipment.
  • I also pour a little more polyquat in in front of the return since I can't pour it in around the pool.

For Opening - I de-winterize in early April when the outdoor temp starts to get above 60 degrees since the water right below cover will heat up and cause algea ring around pool without circulation
  1. Install SWG bypass (I don't install SWG until water is balanced, and it doesn't work until water is warmer anyway)
  2. Remove all plugs (I just release cover where needed
  3. Turn on pump and set to run 3-hours per day
  4. Add liquid chlorine to bring up chlorine level
  5. Add Baking soda to bring up Total Alkalinity (I do this through skimmer, probably not reccomended...)
    1. Usually PH is good after TA is in proper range
  6. Add & balance Stabilizer
  7. Install SWG when water is above 60 degrees and balanced
  8. I normally remove the cover a week before Memorial day weekend with just a little algea around the water line that easily brushes off
  9. SLAM & Ready to start the season
 
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