solid winter cover with cover pump on top emptied the pool

[mitzie]

This year I was using a solid winter poly tarp cover with a little giant automatic APCP-1700 1/3 HP 1800GPM pool cover pump left on the cover continuously in the automatic mode. After 4 months I found the winter cover drooped down 3 feet and I took the winter tarp cover off to find only 6 inches of water in the shallow end and 5 feet in the deep end. After spending tons of time and money trying to find a leak the conclusion is so far there is no leak. Pool repair mechanic told me the cover pump used is so heavy and powerful and the tarp, even though advertised as solid, still is fabricated with a weave, and despite being advertised as solid, still has some porosity (second year for this cover) so a strong heavy pump such as this one is able to pull the tarp cover into its bottom sump and vacuum water right out from the pool. He claims he has seen this happen many times and tries to make as many pool owners aware of this as possible to avoid wasted time and money with expensive testing. His remedy is to use a smaller and lighter cover pump or use the automatic pump intermittently and not to leave it on continuously. Does anyone else have a similar experience? Can this happen without a visible tear or hole in the winter cover?

 

[Kiss4aFrog]

I'm using a smaller pump that normally circulates water in a couple hundred gallon pond. I plug it in when I need it. The woven plastic tarps will bleed water through them over time and by the third or fourth year leak pretty good. IMHO, You have a great pump you just need a better cover.

 

[rhaas12321]

It happened to me also with a 3 year old cover and a brick weighing down a siphon hose. I was so worried in the spring that I had developed a leak but that was not the case. Just a porous winter cover. I was thankful and now I pull out the siphon hose

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[mitzie]

It has been a week since I refilled he pool and the water does not drop down at all. Could not find a tear in the solid winter cover despite removing it for inspection and then reapplying it over the pool. I did the flashlight test to actually visualize the weave spaces. It does let light thru and you can see tiny gaps between the weaves especially where it stretches out. This is very different than a vinyl cover such as that used in a Coverstar or Coverpools motorized automatic pool cover product. The vinyl motorized covers are quite heavy and are fitted loose to allow some dropping due to leaves and larger pumps. It seems to me any porosity in a cover has to compensated by lateral tension or it will sink into pool water with any additional weight on it. I had tried one of those mesh winter covers in previous years with water bags for support and it was a total failure. It sinks into the pool water and you cannot use a pump at all because it pumps out the pool water rather than float the cover back up. So I had to get rid of it. The automatic vinyl cover is not good in the winter because once the ice on top of it is more than 6 inches thick it will displace the water underneath the cover and rip the bead out of the track because it has no spring loading to it just excess vinyl slack. Chopping ice on top of a motorized cover with steam like they do on house roofs is very difficult. That leaves us with a spring loaded safety cover as the best option for the harsh winter snow and ice. The spring loaded covers have limited shear strength and have been known to rip apart with a lot of sharp heavy ice and snow loading but you have the option to release the springs with the tool and allow it collapse down before it tears. I believe its best to remove snow with a broom before it melts and refreezes to ice, if you can get to it, or just leave the pool open until snow and ice is done. I am going to fabricate a two stage spring system (one heavy spring in series with a lighter spring) or easier yet a tool adjustable spring anchor threaded extension rod or strap for those bad winter weeks to let out more slack before the safety cover tears or you just give up and release the springs altogether.