Trouble Blowing Out Main Drain - necessary or...?

[Appleman]

Hey All - Closed the pool for the first time this year (few days ago). Blew out all lines, antifreezed skimmer lines, etc.. but I haven't been able to blow out the main drain line with any of the shop vacs I've tried (all the way up to a 6.5 HP shop vac). I've come across a few viewpoints on the topic that seem to contrast each other. One viewpoint which is, it's very important to blow out the main drain (and close valve once air is visible coming from main drain to create the airlock) in order to properly winterize the line and several pool companies I've spoken to locally (in Upstate NY) say they don't blow out the line but simply pour pool antifreeze down it and call it a day (and have never run into an issue). Sitting here wondering is it simply enough to put some pool antifreeze down the line or do I really need to make the investment in something like a cyclone that can blow out the line?

Thanks to you all in advance! Awesome forum.

 

[ajw22]

How deep is your main drain?

The frost line around Syracuse is about 36".

If your MD is below 36" it should not freeze and need to be "blown out".

What you do need to do is get the water out of the pipe leading to the MD down below 36" or get antifreeze into it.

Closing Pool for Winter - Further Reading

www.troublefreepool.com

 

[Bperry]

Hey All - Closed the pool for the first time this year (few days ago). Blew out all lines, antifreezed skimmer lines, etc.. but I haven't been able to blow out the main drain line with any of the shop vacs I've tried (all the way up to a 6.5 HP shop vac). I've come across a few viewpoints on the topic that seem to contrast each other. One viewpoint which is, it's very important to blow out the main drain (and close valve once air is visible coming from main drain to create the airlock) in order to properly winterize the line and several pool companies I've spoken to locally (in Upstate NY) say they don't blow out the line but simply pour pool antifreeze down it and call it a day (and have never run into an issue). Sitting here wondering is it simply enough to put some pool antifreeze down the line or do I really need to make the investment in something like a cyclone that can blow out the line?

Thanks to you all in advance! Awesome forum.

Pouring antifreeze down the pipe will just dilute the antifreeze over time since the drain isn’t sealed. You need to get all the water out of the pipe that’s above the 36” frost line mentioned above.

It’s possible your shop vac is pushing the water 36” down enough to airlock it, but the only way to know for sure is to see air bubbles coming out of the drain. My shop vac wouldn’t handle my drain but the cyclone does very well. It does sprinkler lines as well.

 

[Newdude]

So here how the air lock works, like the ole finger on a straw trick. The air pushes the water down the green 'up pipe' and out the horizontal pink pipe under the pool. The green pipe may go up immediately and then to the pad or have a slow rise but either way omce its clear and locked, the water can't push the air out to get in there like it can glug glugging into the pink pipe. This is also why antifreeze is pointless with the drain side open. It'll ooze out possibly in minutes.

The only way to know you pushed it low enough is to see bubbles out the drains, but as long as you cleared the frost line, you're still good. (Pictured with skinny green line).

 

[Appleman]

Thanks for all the feedback friends.. I'm thinking the purchase of the cyclone may be a good investment now given I plan to handle close myself moving forward.. Ya'll own a cyclone or something similar that does the trick? Curious what the more - maybe slightly affordable options are.

 

[Appleman]

I've also got one of these toro leaf blowers | Toro (340 cfm) - but don't have an attachment/adapter to convert the rectangular looking opening to something that would fit over a circular pipe. Perhaps they make one.

 

[PoolStored]

Ya'll own a cyclone or something similar that does the trick?

Yes. Get the cyclone and don't look back. Saves soooo much hassle...

 

[Bperry]

I've also got one of these toro leaf blowers | Toro (340 cfm) - but don't have an attachment/adapter to convert the rectangular looking opening to something that would fit over a circular pipe. Perhaps they make one.

I have the cyclone, but you could try the leaf blower. If it’s not too burdensome to do so.

 

[Newdude]

I plan to handle close myself moving forward..

As a once a year device, it should outlive you. They wanted $700 something to close last year. The only reason I considered it was I would have next to no warning when my new cover came in and being late season with less work, they were going to install it right away. I choked at the seven hun part and didn't hear if it was $762 or $735.

I made them agree to give me a few days warning and when they didnt call and shower up on a Friday, I kicked them out which gave me the weekend to close.

I've also got one of these toro leaf blowers | Toro (340 cfm) -

Handheld blowers don't have enough ooomoh to clear the skimmers/returns. I have a big gas model and it didn't push any water at all. My large shop vac clears the upper lines surprisingly well. My backpack blower (764 CFM at the nozzle) makes a geyser out of the returns and skimmers but still doesn't have the power to send air out the drains.

I'm going to play with it this year and try 2 shop vacs both in parallel and series and if that doesn't work tape splice my compressor hose with the shop vac and/or backpack blower. They both have the CFM and only need a couple PSI boost.

 

[Appleman]

Out of curiosity, any idea if something like this would work or stick solely with cyclone? XPOWER 3 HP Indoor/Outdoor Commercial Inflatable Blower Fan for Bounce House, Jumper, Game and Display Structures BR-292A - The Home Depot

 

[Bperry]

Out of curiosity, any idea if something like this would work or stick solely with cyclone? XPOWER 3 HP Indoor/Outdoor Commercial Inflatable Blower Fan for Bounce House, Jumper, Game and Display Structures BR-292A - The Home Depot

To even try it, you’de need to find a 5” diameter hose to connect to it and then neck the hose down to 1.5”-2.0” so it fits on a skimmer. Add that to the cost.

 

[Newdude]

I have a similar large one from an blow up water slide and when I dusted it off to try it I put my hand over the exhaust and while it had tons of air, there was no pressure whatsoever. I didn't even try it.

 

[Appleman]

Roger that. Thanks all.

 

[Flowerchld]

Out of curiosity, any idea if something like this would work or stick solely with cyclone? XPOWER 3 HP Indoor/Outdoor Commercial Inflatable Blower Fan for Bounce House, Jumper, Game and Display Structures BR-292A - The Home Depot

If a 5 or 6 HP shopvac can't blow out the main drain, how could this 3 HP blower? And what hose would you use?

 

[Bperry]

If a 5 or 6 HP shopvac can't blow out the main drain, how could this 3 HP blower? And what hose would you use?

HP has nothing to do with it. It comes with a hose and you can find a PVC fitting to connect it to your system or just jam the hose in an open pipe.

 

[Flowerchld]

HP has nothing to do with it. It comes with a hose and you can find a PVC fitting to connect it to your system or just jam the hose in an open pipe.

What DOES have to do with it? I'm reading people using 2 or 3 HP shopvacs and others saying you need 5 or 6 HP. Why can a lower HP blower blow out a main drain, but a higher powered shopvac can't? That makes no sense to me? Some people use 5 psi on a compressor and some say you need 20 to 30 psi. I guess I'm looking for the science behind it because I'm having trouble blowing out my main drain and don't want to waste money or time on ineffective tools.

 

[Newdude]

The outlet on the cyclone is smaller than a shop vac hose with no restrictions such as the filter in the shop vac, so it has alot more oomph. But now that you made me type that out loud, I'm totally going to try again reducing the hose size and removing the filter. It still may not be enough though as it's using the exhaust and the shop vac is designed for max suction, not max blow.

Here was my close last year.

Closing with shop vac.

Today was the day for closing and it went great with a 6HP shop vac. I hooked my blower up for fun after, and there really wasn't much left but some spray. Anywho I wanted to do a write up for all the folks wondering if they could save a chunk of change and tackle their own closing...

www.troublefreepool.com

Compressors have the PSI but not the CFM. And once any air escapes, they lose all their momentum, so they're iffy at best.

 

[Bperry]

What DOES have to do with it? I'm reading people using 2 or 3 HP shopvacs and others saying you need 5 or 6 HP. Why can a lower HP blower blow out a main drain, but a higher powered shopvac can't? That makes no sense to me? Some people use 5 psi on a compressor and some say you need 20 to 30 psi. I guess I'm looking for the science behind it because I'm having trouble blowing out my main drain and don't want to waste money or time on ineffective tools.

CFM and PSI combined are what’s needed. Everyone’s drain and plumbing is different and so some people can blow out shallow drains with a shop vac and some can’t.

HP is the rating of the motor in the fan or blower and is not directly connected to how much air and at what pressure it moves. Those are related to the fan blade size and design in the shop vac vs the blower in the cyclone. It’s different air moving technology.

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[wireform]

Buy once cry once but be happy for ever. I've been closing pools for some time and rigged every combination imaginable but will say the cyclone blower is all what they say it is. It'll make the main drain bubble like no other without much trouble. The only place antifreeze isn't used is the main drain if you follow here and airlock properly.

 

[Bperry]

CFM and PSI combined are what’s needed. Everyone’s drain and plumbing is different and so some people can blow out shallow drains with a shop vac and some can’t.

HP is the rating of the motor in the fan or blower and is not directly connected to how much air and at what pressure it moves. Those are related to the fan blade size and design in the shop vac vs the blower in the cyclone. It’s different air moving technology.

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Fans and blowers are commonly seen in homes, schools, offices, garages, and almost all sorts of industries. They’re often thought to be the same device since they both circulate air, but they do have distinct features and functions that separate one from the other. This article will tackle fans...

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Also for reference, my 6HP rigid shopvac could not blow out my 9’ deep main drain but could blow out my returns and skimmers. The cyclone does it all.