Hey Guys,.. thanks for the reply.

So the "trouble" I had in the spring when I removed the cover was that
some of the liner had come out of it's track around the top edge...
about 6' worth of the liner was off and sagging into the pool. Of
course, i didn't know this 'til the cover came off as what I used to do
was fill the pool underneath the cover to it's proper height and then
take off the cover.

So I had to call the pool shop, they drained the water down a foot or
so, and stretched the liner back up and fastened it back into the
track. It's fine now but the pattern looks a tad distorted on that
side.

This is the 3rd year I'm using this new pool cover, the one before this
had a couple of large holes in it that I believe allowed rain water to
get in and keep the water level at a certain threshold over the fall
and spring. But with this new cover, each year, the water level drops
precipitously during the non-freezing months that the pool cover is on.

The reason the pool shop recommended removing the cover is because with
the water level so low the snow and ice on top are causing it to pull
in the walls of the pool. You can see this on my pool as it sort of
looks like the wall is bent into the pool.

I'm not afraid of having to clean up the water in the pool and there
are literally no leaves left on the trees around me. So as long as the
liner isn't in danger of drying out (the bottom corners are still under
1 to 2' of water), then I'm all set.

As for there being a pinhole in the liner, this is what I thought the
past 2 years when I opened the pool with so little water in it. So
during the year I kept a close eye on the water level and sure enough,
it was as constant as usual, with there being the normal amount of
evaporation as always. The cover has only been on since Sept 20 or so.
So that's only 2 months. There's no way during 2 months of the summer
that I lost this much water.

I saw another posting on WaterNet (http://waternetonline.com/index.asp)
that said pool covers usually develop undetectable pinholes in them so
that when you have a large amount of rain sitting on top, the pressure
also causes water from the pool to seep through so that when you pump
off the cover (as I do very diligently), you're also pumping off some
of the pool water.

Also, my pool cover is oversized for my pool... it's a 24' cover for a
21' pool. I did this to give it some room to slide when the snow starts
weighing it down.

I was thinking about getting a leaf cover instead but what does that do
to your water level with all the rain getting in there over the fall
and spring not to mention the snow that eventually melts. Do you pump
it out to keep it below the return? or just keep the return open so it
seeps out? It would actually be pretty cool to open my pool this year
and already have all the water I need in there! :-)

Thanks for your help guys,

G