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Thread: Air at top of filter tank and tiny bubbles at inlets.

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    Air at top of filter tank and tiny bubbles at inlets.

    I've always noticed very small air bubbles coming out of my return inlets. It seemed particularly bad recently, so decided to look into it a bit. I bled the air out of the top of the filter and the bubbles stopped, but the fix was only temporary. Eventually, the bubbles returned, and the top of the tank was once again filled with air.

    Logic points to a suction side leak, but it strikes me that when using a kreepy krauly as I am, there will consistently be a small amount of air pulled into the system from things like small leaks in the cleaner hose (which I have never been able to fully stop), or from the cleaner getting too close to the surface (which it will do once in a while in certain circumstances.) In other words, getting a small flow of air in the system over time seems unavoidable when using a kreepy krauly. Does this mean that the bubbles in the system and the air at the top of the filter tank are just a normal side effect of using the Kreepy Krauly?

    This filter is a Purex SMBW 2060, which has an air vent tube at the top of the tank. As I understand it, this should evacuate the air at the top of the tank, but according to my reading, the air is routed to the return line, so this would still result in the inlet bubbles as long as the level of the water in the filter was below the level of the vent tube. Is this correct?

    Thanks,

    Larry
    Los Angeles, CA -- 22K gallon in-ground plaster pool with spa, built around 1980, replastered around 2009-2010.
    Pentair Intelliflo VS (variable speed) pump and Quad 100 DE filter. Older "MiniMax" gas heater. Pentair Rebel cleaner.
    NO SWG - Liquid Cl only. Taylor K-2006 test kit.

  2. Back To Top    #2
    Mod Squad JohnT's Avatar
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    Re: Air at top of filter tank and tiny bubbles at inlets.

    I suspect you have another leak. Do you have bubbles in the pump strainer basket?
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

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    Mod Squad Bama Rambler's Avatar
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    Re: Air at top of filter tank and tiny bubbles at inlets.

    It's surely a suction side leak. I use a suction side cleaner and never have any bubbles. My bet is it's not your hose that's causing the leak. Check all the normal places.
    Skimmer creating a vortex.
    Vac plate not sealing well.
    Pump strainer lid
    Pump strainer drain plug.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

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    Re: Air at top of filter tank and tiny bubbles at inlets.

    The reason that I suspected the Kreepy hose is that the leaf trap installed in-line with it always gets a sizable air bubble in it. It fills with air until the bubble is big enough to start getting sucked into the other end of the cylinder a little bit at a time. If I tip the canister end up so that all the air is pulled out of it, it fills again within a few minutes. Unfortunately, it's really hard to tell if this is enough to account for the amount of bubbles I'm seeing at the jets.

    This means that I DO have a leak in the Kreepy line, but it doesn't mean that I don't have another leak elsewhere. My plan is to disconnect the Kreepy and just run the skimmer (no bottom drain), which will prevent air from entering the skimmer. If the bubbles stop, I'll know that it's the Kreepy hose. If the bubbles continue at the same or only slightly reduced rate, I'll know that the Kreepy hose is not a major factor. If they reduce but don't fully stop, it will indicate that the Kreepy hose is a contributing factor, but that there is at least one other leak as well.

    Bama - do you use a leaf trap canister in line with your cleaner, and if so, does it always get air in it like I described?

    John - I do notice some "activity" in the pump's view window -- i.e. what appears to be a small amount of tiny bubbles streaming past very quickly. It doesn't look like very much (it seems like it would be less than the amount of air coming out of the jets), but it's hard to tell since the water is moving so fast right there.

    Just to clarify, am I correct in assuming that the leak would have to come from the suction side since the pressure side would only push water out? I do have a couple small leaks on the pressure side, but I figured that these could not put air into the stream.

    Thanks,

    Larry
    Los Angeles, CA -- 22K gallon in-ground plaster pool with spa, built around 1980, replastered around 2009-2010.
    Pentair Intelliflo VS (variable speed) pump and Quad 100 DE filter. Older "MiniMax" gas heater. Pentair Rebel cleaner.
    NO SWG - Liquid Cl only. Taylor K-2006 test kit.

  5. Back To Top    #5

    Re: Air at top of filter tank and tiny bubbles at inlets.

    Quote Originally Posted by Bama Rambler
    It's surely a suction side leak. I use a suction side cleaner and never have any bubbles. My bet is it's not your hose that's causing the leak. Check all the normal places.
    Skimmer creating a vortex.
    Vac plate not sealing well.
    Pump strainer lid
    Pump strainer drain plug.
    Have you looked at any of these things?

    The pump strainer drain plug may have an o-ring or flat washer. Remove it, take the o-ring or washer to the kitchen and wash with dishwashing soap and scrub with a toothbrush, then grease with silicone lube or similar product from a pool store. (not Vaseline). Same thing for the o-ring in the lid to the pump basket, wash and lube. Those are really easy to check. You've probably already looked to see the pool water level is correct for if it is low the skimmers can suck air. Also see that skimmers are working correctly, if the weir door is hung up on debris the skimmer can suck air.
    23,000 gallon in ground pool with rock waterfall and spillover spa, Aqualink control system, Polaris 380 cleaner, Purex Triton Clean&Clear Plus cartridge filter. Located in The Woodlands, Texas.

    Pool owner since Nov 2008, Trouble Free since April 2009. Happy to help when I can.

  6. Back To Top    #6

    Re: Air at top of filter tank and tiny bubbles at inlets.

    Quote Originally Posted by anonapersona
    Quote Originally Posted by Bama Rambler
    It's surely a suction side leak. I use a suction side cleaner and never have any bubbles. My bet is it's not your hose that's causing the leak. Check all the normal places.
    Skimmer creating a vortex.
    Vac plate not sealing well.
    Pump strainer lid
    Pump strainer drain plug.
    Have you looked at any of these things?d
    Yes.

    I usually use a Vac-mate in the skimmer instead of a vac plate (to continue to have skimmer running when cleaner is running), but this in and of itself does not appear to be causing the problem. The water level is high enough that I can visually confirm that no air is being pulled around or through the vac-mate seals. I can "make" air get past the Vac-mate by making large enough waves in the pool so that air is pulled through the skimmer section of the Vac-mate, but it's very easy to hear when this happens, and it doesn't happen unless the water level gets very low, or unless I force it to happen.

    This is moot at the moment, however, since I've removed the vac-mate for my tests, and the vortex does not appear to be powerful enough to pull air all the way down. This should take the cleaner, vac-mate, and skimmer out of the loop and reveal if I have another leak elsewhere.

    The pump strainer drain plug may have an o-ring or flat washer. Remove it, take the o-ring or washer to the kitchen and wash with dishwashing soap and scrub with a toothbrush, then grease with silicone lube or similar product from a pool store. (not Vaseline). Same thing for the o-ring in the lid to the pump basket, wash and lube. Those are really easy to check. You've probably already looked to see the pool water level is correct for if it is low the skimmers can suck air. Also see that skimmers are working correctly, if the weir door is hung up on debris the skimmer can suck air.
    There appear to be two plugs at the base of the pump basket (i.e. square headed, threaded plugs.) I'm not sure why there would be two, so I'll have to look into this and see if I can dig up a manual. The pump looks pretty old, and much of the writing is no longer readable, so this may not be easy. On top of that I'm a bit tentative about trying to remove a plug for fear of them being frozen, and I don't want to damage something and make things worse. I can, however, re-grease the basket o-ring. I just ran out of silicone plumber's grease, however, so I haven't done this yet.

    At this time the pump has been running without the vac-mate and cleaner (i.e. "skimmer only") for about a half hour. When I started it I bled the air out of the filter, eliminating the inlet bubbles. I checked it just now and there were still no bubbles from the jets, but I re-bled the filter tank and there was a bit of air in it. It was a pretty small amount, so I'm not sure if it was "new" air, or just some residual bubbles in the system took a little while to make their way to the top of the filter tank. I'll have to let it run for a while to tell anything for sure, but at this early stage of testing it's looking like at least a decent portion of the air is coming from the cleaner hose. This makes sense given that I know the hose is pulling in some air (as shown by the leaf trap canister filling with air.)

    I'll have to do more tests -- with and without the cleaner -- to get a more accurate picture. I did get a few new Kreepy hose sections, but these leaked REALLY badly under the end fittings, MUCH worse than my current hose. I'm not sure what to do about this other than find a different source for hose sections. Apparently, there is a wide range of quality differences between them.

    Bama -- regarding my earlier question, do you get air in a leaf trap canister?

    Thanks again,

    Larry
    Los Angeles, CA -- 22K gallon in-ground plaster pool with spa, built around 1980, replastered around 2009-2010.
    Pentair Intelliflo VS (variable speed) pump and Quad 100 DE filter. Older "MiniMax" gas heater. Pentair Rebel cleaner.
    NO SWG - Liquid Cl only. Taylor K-2006 test kit.

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    Re: Air at top of filter tank and tiny bubbles at inlets.

    Got any shaving cream? We just located a bad o-ring in a Jandy valve body by lathering up the pump and all piping on the suction side of the spa, bit by bit. The o-ring didn't look bad but as I washed it with dish soap I could feel the tiny cracks in it. Lubrication sealed it for now and I was able to get the parts locally. If the pump drain plug is the cause you may not see much bubbles as they are sucked into the pump and filter without hitting the lid very much, but they still go to the filter and eventually to the pool.

    I know you are hot on the trail of the leaking hose sections, but still it could be more than one source.
    23,000 gallon in ground pool with rock waterfall and spillover spa, Aqualink control system, Polaris 380 cleaner, Purex Triton Clean&Clear Plus cartridge filter. Located in The Woodlands, Texas.

    Pool owner since Nov 2008, Trouble Free since April 2009. Happy to help when I can.

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    Optica's Avatar
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    Re: Air at top of filter tank and tiny bubbles at inlets.

    If you find its the leaf canister that is leaking...here is one way you might be able to fix at no cost.

    I use a leaf canister for my navigator pool cleaner and after about a year..it starts leaking air into the canister which gets sucked into the pump. The leak is mostly around the removable lid seal. I've re-lubed the o-ring and tightened everything but could not stop the small leak. I replaced it and was good for about a year, then it started again with the new canister, exact same symptoms. This is the large canister which costs about $60-70 so my fix for this instead of buying a new one every year is to keep the canister below the water surface so no air can get in. I tie it to the hose connection where it plugs into the pool wall which keeps it in position under the surface. problem solved.
    ___________________________________________________
    12,000 Gal IGP, Gunite/Plaster, Pentair DE & Pump, Heliocol Solar, K-2006, BBB'd & Borated.

  9. Back To Top    #9

    Re: Air at top of filter tank and tiny bubbles at inlets.

    I definitely have more than one leak. One is the Kreepy hose, but the other is going to be a lot harder to find. On this note, I know that it's the hose and not the actual leaf trap canister since it still fills with air even while it's completely submersed.

    Regarding the shaving cream, I assume that the idea to watch for it to disappear at a particular spot as it's sucked in, but I have a couple questions. First, is there any danger of getting foam in the pool by doing this? I've heard that it can be difficult to get rid of foam, and I don't want to add another problem to the mix. Second, how obvious is the effect? I've used soap bubbles to find air leaking "out" of a system, which produces very obvious results, but I've never used foam to spot "inward" leaks, and I'm not sure how noticeable it might be.

    Thanks,

    Larry
    Los Angeles, CA -- 22K gallon in-ground plaster pool with spa, built around 1980, replastered around 2009-2010.
    Pentair Intelliflo VS (variable speed) pump and Quad 100 DE filter. Older "MiniMax" gas heater. Pentair Rebel cleaner.
    NO SWG - Liquid Cl only. Taylor K-2006 test kit.

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    duraleigh's Avatar
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    Re: Air at top of filter tank and tiny bubbles at inlets.

    I don't understand the reference to shaving cream, either. I can't see it as very effective on a suction leak.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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    Re: Air at top of filter tank and tiny bubbles at inlets.

    Shaving cream was what we used and it did locate the suction leak source for us.

    I will point out that the nice thing about shaving cream is that it is thick enough to stay where you put it. You can put a not too thick coat on a lot of areas, sides, bottoms, and it stays put if everything was dry to start with. Spraying water on those areas before was not effective for me.

    Shaving cream was something my dear hubby found while looking online. So nice that he joined in on the search as he went to different sites than I did. Theory is that the foam will suck into the leaking site, forming a neat little cone that points to the problem. I'll admit, we never really saw it suck into the site like it was supposed to but we foamed one area at a time and waited a while to observe the bubbles in the pump before proceeding. Maybe it was put on too thick, I dunno.

    First we did the pump basket lid, a likely suspect as it does spit water when the pump goes off. No leak there. Then each pipe joint along the way, no not that. Those I had tried with water, unsuccessfully, last winter when the heater problem first started. Then finally we covered the Jandy valve actuator and the valve itself, the bubbles in the pump basket stopped. Never did see the foam suck in to point to the leak as we had read it would, apparently the foam itself was barrier enough to stop the air flow.

    Actually that was a good thing to notice, for it should have been a clue that simply lubing the valve parts would fix the air leak. At some point I found the owners manual for the Jandy Neverlube valve and actuator that said that the valve O-rings should be lubed annually. I know that had not been done for 9 years, 3 years that we've been here and no receipts in the file for prior.

    So, anyhow, then we washed off the shaving cream, part by part, hoping that the bubbles would re-appear but they did not. Like you, I worried that the spa might start foaming or smelling minty, but there was no obvious drawing in of shaving cream and no foam in the spa. Even if it had sucked in any shaving cream, I doubt it could have taken in more than a teaspoon or so of it and that is insignificant in a spa or pool.

    After we lubed the valve O-ring, the bubbles in the spa continued and from my reading I suspected the pump drain plugs. So we removed those gaskets, washed, lubed and replaced then and it was after that that the bubbles in the spa finally stopped. So I figure there were two leaks, the O-ring the Jandy valve body which we saw in the pump basket and was interferring with the heater, and one of the drain plug gaskets which continued to let air into the spa after we fixed the Jandy valve o-ring.

    For now, silicone lube seems to have sealed the air leaks. Before winter we will replace all the o-rings in all the valves that we tested; the chlorinator, the Jandy valves, the Jandy stem, the drain plugs, and the pump basket lids.

    Bravo to Warehouse Pool Supply for beating online prices by 60%, and I shopped for hours online.
    23,000 gallon in ground pool with rock waterfall and spillover spa, Aqualink control system, Polaris 380 cleaner, Purex Triton Clean&Clear Plus cartridge filter. Located in The Woodlands, Texas.

    Pool owner since Nov 2008, Trouble Free since April 2009. Happy to help when I can.

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