1st time closing - question on water level compared to lowest return vs skimmers

[GregOP]

I've been scouring this forum for a few months now, as I recently bought a house (6/24) which has a 33,000 gallon in-ground pool. It took me about 8 days to get the water chemistry where it should be, but thanks to this forum, I was able to do so. I've been using about 1 gallon of chlorine every 36-48 hours and maintaining proper FC levels for my CA level. This forum is fantastic!

That being said, closing time will be here before I know it. My wife insists I let the pool guys do it the first time around, which I may reluctantly agree to. However, I want to ensure I personally fully understand the closing process so I can take it over next year.

I've read through a few different closing guides and posts here and one thing that I'm a bit perplex on is the water level. It says to drain 6" below the lowest return\skimmer. My pool has 2 skimmers, and my attached spa has an additional skimmer. The pool has 2 additional 'holes' in it, in line with the main drain, but higher up in the pool. They have 'dispersion' covers or something of that nature (just a plastic cap that has a 1" gap to allow water to flow around the cap). There's one that is about 6ft deep, and another in the shallow end which is about 3.5 ft deep. Then, finally, there's a single jet coming out of the side on the deep end which is used to circulate the water and is connected to a booster pump which I have to manually operate. When I had a pool person come out early on, he had mentioned that both of the additional 'holes' in the bottom of the pool were returns, not drains, which I suppose makes sense to me.

So, does that mean I have to drain my water to 6" BELOW the lowest return, which is about 6 ft down. That means I'm going to have to drain a large amount of the pool water (perhaps 70%?) and the water level will end up about 6.5ft below the skimmers. That just doesn't seem right to me, but perhaps I'm confused.

In the pool equipment room, I've got some valves I can use to control the skimmer and main drain lines. So one line coming from the pool is marked main drain, the other line coming from the pool is marked skimmers. This seems to reinforce the idea that those 2 additional holes in the bottom of the pool are indeed returns.

 

[samt]

No you don't need to drain below the returns. You can blow air thru the lines and plug them under water just fine. You wont get 100% of the water out but you will get most of it out. And the water that's left will be below frost line and wont freeze anyway. Just have someone help you when you put the last plug in, then they can shut off the blower/ compressor at the pad and switch the valve to create an air lock.

I assume the low and high return are on the same line, so I would plug the low one first and push all the water out the top one. When it bubbles for a min. Plug it , then the air will start pushing water out the main drain. When you see the main drain bubbling air, turn the main drain valve to off. That creates an air lock in the line.

 

[GregOP]

Ok, I think that makes sense. However, are you saying that if I hook the compressor up to the main return pipe in the pool equipment room, that after I plug the first return, the water will start to bubble out of the main drain? I would think that the air would only come out of returns at that point, and I'd have to blow air into the line labeled 'main drain' in the pool equipment room in order to blow out the main drain, independently from the return lines.

That being said, how exactly do you plug the return when it has the dispersion plate on it (or the main drain cover for that matter)? Do I have to unscrew it and then shove an adjustable rubber stopper into the line? Or is there a better way? Unscrewing things underwater doesn't sound like a lot of fun.

Since I have a valve for the skimmers and the main drain, I assume this is essentially the process:

1.) Blow air out of the main return line in the equipment room while having the low return plugged. Wait for bubbles in the high return, then plug it.
2.) At this point, air comes out of the low return only, plug it and simultaneously turn off the compressor. I'm assuming that when I am blowing air into this main return line in the pool room, that the pipe only goes to the returns and nothing else. So if I had both return holes plugged, I'd have to stop blowing or risk bursting the pipe. Is that right?
3.) Now that the returns are free of air, hook the compressor up to the main drain line in the pool room. After bubbles come out for a minute, plug the main drain. I assume I have to buy some huge main drain plug that I can put over top the main drain?
4.) Repeat the same process for both skimmers.

Then I have to do the same process for the spa, which has 1 skimmer, and 1 drain, and 1 return (although the return looks like a little jet - it pumps cold water when the spa is on).

Thanks for the help.



edit: Looking at some of the other posts on here, I think I know why I'm a bit confused. I don't hook the compressor up to the individual lines that go into the concrete pad and to\from the pool. I should hook the compressor up right after all the filters so that I'm essentially blowing on the skimmers\returns\main drain all at once. Then, I just start plugging things off in the right order. Once I get to the main drain, I can just turn the knob to shutoff the pipe and water may go in just a tad, but will be airlocked and good to go. So how do I plug the returns with the dispersion plates?

 

[samt]

If you leave the jandy valve at the pump open on both the main drain and skimmers and start pumping air the first thing that will bubble is the skimmers. As they bubble plug them, next will be the returns and plug them. Last will be the main drain and that's when you turn the valve to off on the main drain side to create an air lock since you can't plug the MD.

The air preasure will always seek the easiest route to escape with less water pressure, by keeping the jandy valve in the neutral position the lines will be blown in the order above because of the water weight in each line.

Hope that makes sense.

There are different ways to do it. But I think this is pretty simple, especially for one person.

 

[samt]

Ok, I think that makes sense. However, are you saying that if I hook the compressor up to the main return pipe in the pool equipment room, that after I plug the first return, the water will start to bubble out of the main drain? I would think that the air would only come out of returns at that point, and I'd have to blow air into the line labeled 'main drain' in the pool equipment room in order to blow out the main drain, independently from the return lines.

That being said, how exactly do you plug the return when it has the dispersion plate on it (or the main drain cover for that matter)? Do I have to unscrew it and then shove an adjustable rubber stopper into the line? Or is there a better way? Unscrewing things underwater doesn't sound like a lot of fun.

Since I have a valve for the skimmers and the main drain, I assume this is essentially the process:

1.) Blow air out of the main return line in the equipment room while having the low return plugged. Wait for bubbles in the high return, then plug it.
2.) At this point, air comes out of the low return only, plug it and simultaneously turn off the compressor. I'm assuming that when I am blowing air into this main return line in the pool room, that the pipe only goes to the returns and nothing else. So if I had both return holes plugged, I'd have to stop blowing or risk bursting the pipe. Is that right?
3.) Now that the returns are free of air, hook the compressor up to the main drain line in the pool room. After bubbles come out for a minute, plug the main drain. I assume I have to buy some huge main drain plug that I can put over top the main drain?
4.) Repeat the same process for both skimmers.

Then I have to do the same process for the spa, which has 1 skimmer, and 1 drain, and 1 return (although the return looks like a little jet - it pumps cold water when the spa is on).

Thanks for the help.



edit: Looking at some of the other posts on here, I think I know why I'm a bit confused. I don't hook the compressor up to the individual lines that go into the concrete pad and to\from the pool. I should hook the compressor up right after all the filters so that I'm essentially blowing on the skimmers\returns\main drain all at once. Then, I just start plugging things off in the right order. Once I get to the main drain, I can just turn the knob to shutoff the pipe and water may go in just a tad, but will be airlocked and good to go. So how do I plug the returns with the dispersion plates?

You got it on your edit. I just hook up to the pump drain screw with my compressor and it blows air thru filter , pump and lines. You don't hook up to the drain or skimmer lines separate.

Sorry, I have no experience with dispersion plates.

 

[Catanzaro]

Please post pictures from different angles of your equipment pad and filter set up. Also, how many returns, skimmers and main drains do you have? It usually helps to have visuals.

If you place the multi-port on recirculate, you then can blow air for the return jets. The suction side (Skimmer & Main Drains) are at the pump. You could also vacuum water out of the skimmers if the water is lowered. Then blowing the remaining water is a breeze. Most people have problems with the main drain.

Please post some pictures and we can give you some ideas of what to do. If you can label the plumbing, that would be great. All depends on the clarity of the piping from the pictures. Thanks