Closing Soon... a bit of a wrinkle (not in the liner!)

[JVTrain]

So water temp is hovering in the mid 60s so too soon to close. Lots of low 40s, some 30s overnight for the rest of this week and not likely to warm up soon. Here's the wrinkle... I have been allowing evaporation to take its course over the last few weeks to lessen the amount I need to drain at close. Today during the last pump cycle of the day, the water is now at the point where the skimmers are sucking some air. Waterfalls into the skimmer baskets rather than a whirlpool. So... for the next several days, I'll have both the skimmer lines closed, only drawing water from the main drain. I think I'll be OK as long as I do some brushing and run the robot a few times for circulation and cleaning. No skimming action so I'll have to hope the leaf intrusion is minimal and run the leaf net daily as well.

I'd rather do it this way instead of adding a couple thousand gallons to bring the water level up for a few days, just to drain it all out again. :?

 

[pooldv]

Sounds like a plan!

 

[JVTrain]

Have been closing the last two days, taking my time, stumbling through it a bit. Blew out the skimmers and returns with my 6.5 HP shop vac with no problems. Cannot get the main drain to bubble. Isolated so that I'm blowing through one skimmer back through the pump and out the MD, no air should be flowing through return side. I get a couple bubbles here and there when I fire up the blower, but then nothing. My blower might be able to do it, but a few leaky joints in the hose connections might be holding me back.

I have also tried using my small pancake compressor hooked up at the pump, but to use that I am pressurizing more volume on the return side of things. I can also hear air leaking out of 2 of the 3 threaded return plugs, so losing pressure there. Thinking of getting 3 expansion plugs for the returns and/or a better sealed vac hose...

 

[zea3]

You can try wrapping your hose connections with rubberized plumber's tape. It should give you a nice seal and it is removable when you're finished.

 

[Catanzaro]

I used the threaded plugs and they leaked. On so tight, that I had to use a wrench to remove them. Too much pressure no good. I would use the black expandable plugs as they seem to work best.

I do not believe the small leak is causing the issue with the MD. If you are pressurizing the system from the skimmer, depending on how long (and thick), the piping is back to the pad and then to the main drain, you may be loosing air because of resistance. Maybe having a shorter distance will help.

Can you isolate the system at the equipment pad and use the shop vacuum there? I purchased the cyclone and created the modified cover at the pump and it was worth every penny. Helped a few friends close pools as well. Out here in NJ, it is a common problem that the MD does not get cleared out very well with a shop vacuum. How about an air compressor with a NPT fitting at the pump housing with everything closed?

 

[JVTrain]

Finally got enough pressure from the compressor at the pump to get bubbles from the MD. Bubbles for about 20-30 seconds until the compressor couldn't keep up the volume. Poured a gallon of AF down the MD line and ran the compressor again. After 10 seconds of bubbles, closed the MD valve. That should be good enough. Next year I'll likely be getting a cyclone to make closing easier.

 

[Catanzaro]

Finally got enough pressure from the compressor at the pump to get bubbles from the MD. Bubbles for about 20-30 seconds until the compressor couldn't keep up the volume. Poured a gallon of AF down the MD line and ran the compressor again. After 10 seconds of bubbles, closed the MD valve. That should be good enough. Next year I'll likely be getting a cyclone to make closing easier.

I am glad that everything worked out regarding the main drain. I am still convinced that unless the temperatures are so cold for an extended period of time, no damage will ever occur with the main drain (because of water depth). But, when it comes to a pool, one should be on the conservative side as the risk is way to great.

This winter, I am going to perform a test. From my downspout, I have a 10-14 foot extension that is 6" below ground level. It is schedule 40 white PVC and all parts are glued together (just like pool plumbing), expect where the downspout meets the coupling and the open end (Like a Pop up Emitter). Because I am curious, but do not want to take a big risk, these will be closed off and a regular flexible extension will stick out of the ground from the downspout.

With my experiment, I will fill up another white schedule 40 PVC and close off on one end and leave open on another end with an elbow. This will be interesting to find out if in the dead of winter, the white PVC will expand from water and crack.