Pool vacuum question

[cood60]

Hi, I have a pool vacuum question:
I am new to pools. Have had my new pool for a few months, been using an auto cleaner.
Decided I better make sure I know how to use the manual vacuum so I tried it today.
My pool is 25K, vinyl, with 2 skimmers, 3 returns plus two more at the steps. Two speed Hayward pump, Sand filter with Zeobrite.
I am afraind this pool is not plummed correctly
To vacuum I followed the following steps:
Pump off, hooked up suction hose to one skimmer
Turned on the pump and filled the hose by sticking it against a return
Closed off the other skimmer.
Two main drains are wide open
The vauum seems to work but suction seems low.
So I closed the main drains about half way. No difference in suction but I noticed the pump started making some noise
I noticed the pump pressure would go from 16 to 8 when the main drains are half to 3/4 closed
The strainer at the pump had lots of air until I turned the main drain back to wide open
I did try closing the main drains all the way, no change in suction
The pool co told me at my orientation, to be careful not to close the main drains too far as the vacume might suck up the vinyl.....not a chance
When i remove the lid from the pump strainer, the water level goes down and must prime itself when turned back on.
The lid has a warning that says to fill the reservoir, before starting the pump....this is not possible as all the water poured in simply dissapears
Any ideas? Thanks, Cush Dobbs

 

[Linkterfur]

As a first step, submerge the hose without it attached to the skimmer, if you have it attached and use the return to fill it with water you are essentially adding air into the pump, which is perceived as a bad thing.

My routine consists of...

1) Shutting the main drain off 3/4
2) hooking the hose up to the vacuum head which is attached to the pole.
3) holding with one hand up to a return that is very near the skimmer that is closest to the pump and wait until all the air has been removed (no more bubbles coming from the hose as well as the hose should no longer be floating on the surface, but floating in the water.)
4) holding the pole with the other, (this took a little practice)
5) lastly I'll feed the hose through the skimmer by pushing the weir down, or taking it off and then in without breaking the surface of the water as to not introduce air.
6) if needed adjust skimmer / main drain valves.

Unfortunately I've never worked with a vinyl pool so I cannot comment as to what might happen.

As for priming the pump, close the valves that are before the pump basket, fill with water. Make sure you open them before turning the pump back on though.

 

[Bama Rambler]

Link follows basically the same routine as I do when hooking up the vacuum.

A couple of things to note.
1) Make sure you're hooking the swivel cuff to the vacuum head and not to the skimmer. That end is not a good seal and it leaks. Not a problem when it's under water but a real issue when it's sucking air.

2) Make sure there are no leaks in the hose or the vacuum plate if you use one.

 

[cood60]

Thanks for the info.
I do not have a swivel end on the hose they gave me, ie both are fixed. what a pain that hose is, it tries to coil up when in the water, constantly pulling against me. I have it laid out in the sun trying to straighten the darn thing!

When I have both skimmers open and the main drain open, there are no bubbles in the pump basket
When I gizmo off one skimmer, other skimmer open and main drain open, it seems to be fine
When I then add closing off the main drain, the pump basket gets violent bubbes and empties itself(Vac is not hooked in yet)
Then I open the main drain, let it fill up, til no bubbles
When I hook up the vac plate and hose, it does fine for a while then starts getting a wee bit of air in the pump basket.
If I then close the main drain 3/4, I get lots of bubbles and even empties the pump basket sometimes, then it trys to fill back up again
I am thinking that maybe the pump is so strong that when it sucks through limited piping, it starts sucking air , maybe through the top on the pump basket??
I am meeting the pool company guy tomorrow and needed some help from you guys so I don't get bamboozled LOL
Thanks

 

[Bama Rambler]

The issue is that you have a suction side air leak when you increase the suction head.

You need to check the pump basket drain plug(s), clean and lube the pump basket lid o-ring, check the suction valves and fittings for leaks. One of those places is probably the problem.

Once you've done all that you should be able to run with one skimmer closed and the MD closed off part of the way. Then you can hook up the vacuum and it should work like it should.

 

[cood60]

That is what I figured, thanks for your input. The pool company's service dept. told me today that there is not a problem. His explanation is that my pump is powerful enough to cause the air bubbles when I choke down the supply of water to the pump. I would have thought that choking the supply would cause the motor to groan and struggle but not somehow let air in. My pump is about 12-16" above the water level. You think his assesment could be true?

 

[Bama Rambler]

Theoretically you should be able to close off the suction completely and not have air enter the system. Practically most every system built will leak air in if you get the suction head high enough. However, you should be able to get a really high amount of suction head before that happens.

With that size pump you should be able to close off everything except one skimmer and it not get air into the system. You should easily be able to get enough suction to vacuum forcefully.

 

[cood60]

Thanks for all the info!