Low Suction Through Vacuum Head

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tdfuller
Pool Enthusiast
Pool Enthusiast
Posts: 12
Joined: Tue 24 May, 2011 21:39
My Pool: in-ground, vinyl, 28000 gallons, one skimmer, DE filter FNS Plus 48 (Pentair)
Location: Charlotte

Low Suction Through Vacuum Head

Postby tdfuller » Tue 24 May, 2011 21:42

Greetings to all! I am an experienced, pool owner for 13 years, and completely self managed pool owner for the last 7 years, except for the installation of my DE filter in 2004 by someone else. I even installed my most existing motor in 2005. But this current issue has stumped me.

Does anyone have suggestions for troubleshooting reduced suction through the vac head end of the hose?

My pool pump, motor and filter appear to run normally without vac hose hooked up, i.e. normal swim operation. The skimmer appears to suck in floating leaves etc normally, the return jets are strong and release no air bubbles or air "fizz."

Several months ago, I noticed my vac head suction pressure became weak. Years ago, if not more recently, the suction was so strong, you could see leaves and algae being sucked in outside the vac head. Not now.

When the skimmer plate and vac head are all hooked up after I use a return jet to prime the hose, as I have always done back in the days when vac head suction was strong, the hose used to have water flowing out the end that I stuck up to the return jet. Now, with the old or new hose, it doesn't "overflow" with water out this end as it used to do.

With the equipment hooked up and attempting to vac, the return jet nearest the pool pump, now typically lets out tons of tiny air bubbles that look like soft drink fizz. At first I thought it was DE.

Here is what I have tried, all to no avail:

1. backwashed DE filter - filter grid assembly is 7 years old
2. removed DE filter, disassembled 7 long and 1 short grids, hosed down thoroughly, reassembled and recharged DE - baseline PSI used to be 1 PSI when it was new in 2004, now, even after full disassembly and cleaning, the baseline PSI is 8 PSI, just a hair less than right after backwash with no reassembly
3. pulled pump basket, checked impeller for debris - none found
4. replaced hose cuff on the end of the hose attached to the skimmer plate - there was a small tear that I previously had used Monster Tape to cover
5. replaced entire vac hose with a brand new hose
6. tried vac on WASTE setting to see if the filter itself is an issue
7. tried vac on RECIRC setting to see if the filter itself is an issue - knowing on this setting any debris sucked up would be sent right back out the return jets

Any reasonable suggestions are appreciated!

Thank you!

Todd
Charlotte, NC


poolboy911

Low Suction Through Vacuum Head

Postby poolboy911 » Sat 28 May, 2011 06:01

Could be your pump is getting old and is not pumping so well anymore.

The air in the return line suggests a leak on the suction side. Check pipes for obvious drips and make sure the pump cover o-ring is in good condition.
SPMG
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Posts: 14
Joined: Wed 08 Jun, 2011 06:39
Location: Spain

Low Suction Through Vacuum Head

Postby SPMG » Wed 08 Jun, 2011 09:09

Hello,

Try holding the vac head off the floor to see if you still get 'fizz' at the jets. if you don't still get 'fizz' there is a leak somewhere on the suction side of the pump and that is allowing air into the pump, causing cavitation and reduced circulation - hence less suction at the vac head.

When the vac head is in contact with the floor of the pool the vacuum within the suction side is increased.
It may be that you have a small leak somewhere in the (skimmer) suction pipe, probably at one of the joins in the pipework, that is only evident when you have this 'increased' vacuum.

You can test for this by partially blocking-off the skimmer socket with a credit card or similar (do this gradually) and looking for the point that 'fizz' re-occurs. If you have a leak in this pipe apply LeakSealer from Lo-Chlor or a similar product. Follow the instructions carefully.

Good Luck.

SPMG



Regards

SPMG
tdfuller
Pool Enthusiast
Pool Enthusiast
Posts: 12
Joined: Tue 24 May, 2011 21:39
My Pool: in-ground, vinyl, 28000 gallons, one skimmer, DE filter FNS Plus 48 (Pentair)
Location: Charlotte

Low Suction Through Vacuum Head

Postby tdfuller » Wed 08 Jun, 2011 09:37

Hi SPMG

I thank you for your reply and suggestions. I greatly appreciate them!

I do have a couple of questions. If I still get the "fizz" with the vac head off the floor, can I still use Leak Sealer by Lo-Chlor, even though it says it is not to be used on vinyl liners?

I have a vinyl lined pool.

If I still have "fizz" with the vac head off the floor, what do you think that means; that I have a partial blockage in the lines going from the skimmer to the pump?

Thanks for all of your advice,
Todd
Gator12
Pool Newbie
Pool Newbie
Posts: 1
Joined: Sun 12 Jun, 2011 00:03
My Pool: 13,000 gal
Location: Florida

Low Suction Through Vacuum Head

Postby Gator12 » Sun 12 Jun, 2011 01:20

It could be something as simple as your vacuum hose still has air in it. The tiny bubbles could be some of the air being sucked thru the hose and your system and pushed back into the pool. When I vacuum my pool, I typically close the valve to prevent suction from the main drain and force the pump to suck only from the skimmer. Another way to prime your vac hose is to attach it to vacuum head and pole and drop that in the deep end. After the vac head and beginning portion of the hose are in the pool, slowly feed the hose by hand into the water thus pushing out any air. When you get to the other end of your hose, you should see water. Attach the primed hose as you normally would. Hopefully it is something this simple
tdfuller
Pool Enthusiast
Pool Enthusiast
Posts: 12
Joined: Tue 24 May, 2011 21:39
My Pool: in-ground, vinyl, 28000 gallons, one skimmer, DE filter FNS Plus 48 (Pentair)
Location: Charlotte

Low Suction Through Vacuum Head

Postby tdfuller » Sun 12 Jun, 2011 12:17

Thank you for your suggestions, they are greatly appreciated. Since my original post, I have bought a brand new hose. The new hose does nothing. The same issues still exist. I also took a small Ziplock sandwich bag, removed the skimmer basket, and let the system suck the bag through the skimmer. It made it easily in to the basket of the pool pump basket, indicating that it is highly unlikely there is a partial blockage of the plumbing from the skimmer basket to the pump.

So, I am thinking I have a tiny air leak perhaps at one of the pipe fittings or o-rings, or, my pump is going bad and allowing air in to the system. My pump is more than 10 years old, but, seems to be running strong. I am going to use a bottle of Leak Seal by Lo Chlor to see if that plugs any tiny leaks where pipe fittings are that might be letting in some air when the system is under more pressure with the vacuum installed.
poolowner56

Low Suction Through Vacuum Head

Postby poolowner56 » Mon 01 Aug, 2011 15:40

attn: tdfuller
i am very curious as to how the lo-chlor leak seal worked for you.
i am having problems with my pool pump system, especially when trying to use my vac hose. i recently installed a new motor/pump assembly with new pvc piping. at first i couldnt get proper pressure in the filter. i sealed every joint in the (above ground) pvc piping going to the pump inlet with a marine type sealant... that helped... however, i still get some bubbles/fizz indicated in the pump basket section. when simply running in filter mode, the flow works fine... good outlet at the jet return into the pool... just a few bubbles occasionally... but when i attach the vac hose, etc, the flow goes to nearly nothing.
i also realize that i have a slow pool leak somewhere... the pool loses about 1/2' to 3/4" of water per day.
i strongly suspect that i have a small piping leak somewhere between the skimmer and the pump inlet.
thank you... your response is appreciated.
tdfuller
Pool Enthusiast
Pool Enthusiast
Posts: 12
Joined: Tue 24 May, 2011 21:39
My Pool: in-ground, vinyl, 28000 gallons, one skimmer, DE filter FNS Plus 48 (Pentair)
Location: Charlotte

Low Suction Through Vacuum Head

Postby tdfuller » Mon 01 Aug, 2011 22:39

I have had mixed results with the one jug of Lo Chlor I used. Ultimately, it did not resolve the low suction issue with my vac head. However, I did notice reduced "fizz" coming through the return jets than when before I applied the Lo Chlor. In fact, I don't get any fizz but still get some bubbles during vacuuming only. I have always had some bubbles during vacuuming, even when years ago I had powerful suction when I first started with my new DE filter. For right now, I just have taken a "pause" on completely solving the issue, mainly because on a scale of a 1 to 100, with a 1 being a pool that looks green and trashy, and 100 being a pool that looks clear, blue, with not a drop of dirt on the bottom - my pool stands at about a 90-95 after vacuuming, even with low suction pressure. Sometimes, relatively few small, but heavier particles won't get sucked up, and I have to take a kitchen sieve by hand and scoop them off the bottom. The problem is not resolved - yet - but on the other hand, I am not ready to sink $1000+ in to get a Polaris 9300, some other robotic cleaner or some other possible fix to get strong suction back in play. I think it could be that my DE grids are going on 8 years old. Aging DE grids may not make sense as the culprit, b/c even with the pump on "RECIRC" or "WASTER" the suction is still low during vacuuming. However, I think there is still something to do with reduced suction with an aging filter grid, even with the filter "cut out" of the loop. Eventually, I will replace the entire assembly, and at that time I will know. But for now, an A- looking pool works for me and the DE grid has some good life left in it.
tdfuller
Pool Enthusiast
Pool Enthusiast
Posts: 12
Joined: Tue 24 May, 2011 21:39
My Pool: in-ground, vinyl, 28000 gallons, one skimmer, DE filter FNS Plus 48 (Pentair)
Location: Charlotte

Low Suction Through Vacuum Head

Postby tdfuller » Mon 01 Aug, 2011 22:40

I have had mixed results with the one jug of Lo Chlor I used. Ultimately, it did not resolve the low suction issue with my vac head. However, I did notice reduced "fizz" coming through the return jets than when before I applied the Lo Chlor. In fact, I don't get any fizz but still get some bubbles during vacuuming only. I have always had some bubbles during vacuuming, even when years ago I had powerful suction when I first started with my new DE filter. For right now, I just have taken a "pause" on completely solving the issue, mainly because on a scale of a 1 to 100, with a 1 being a pool that looks green and trashy, and 100 being a pool that looks clear, blue, with not a drop of dirt on the bottom - my pool stands at about a 90-95 after vacuuming, even with low suction pressure. Sometimes, relatively few small, but heavier particles won't get sucked up, and I have to take a kitchen sieve by hand and scoop them off the bottom. The problem is not resolved - yet - but on the other hand, I am not ready to sink $1000+ in to get a Polaris 9300, some other robotic cleaner or some other possible fix to get strong suction back in play. I think it could be that my DE grids are going on 8 years old. Aging DE grids may not make sense as the culprit, b/c even with the pump on "RECIRC" or "WASTER" the suction is still low during vacuuming. However, I think there is still something to do with reduced suction with an aging filter grid, even with the filter "cut out" of the loop. Eventually, I will replace the entire assembly, and at that time I will know. But for now, an A- looking pool works for me and the DE grid has some good life left in it.
yambosha

Low Suction Through Vacuum Head

Postby yambosha » Thu 04 Aug, 2011 11:07

I just replace a motor and sand and now no water is circulating I've been fighting and working hard all summer and now the pool is clean but no water is circulating out of the jets or the skimmer the motor is working. What is it a leak from the skimmer to the pump

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