Bubbles in pump filter basket - I'm STUMPED - multivalve setting filter vs. recirculate

GregN

Well-known member
Jun 18, 2015
50
Central NJ
Hi Folks - I had a new above ground pool installed about a week ago (see signature for pool/pump/filter specs). Since day one, I have had large bubble(s) in the pump basket in the lid. I run the pump on the low speed setting about 10 hours a day and the pool is crystal clear. Running the pump on high speed for about 15 minutes seems to reduce the number of air bubbles to the point where if I turn off the pump, one large bubble will form under the lid about 4" in diameter, but that bubble remains regardless of how long I run the pump.

The pump has held prime over night.

All my plumbing is hard piped 1.5" PVC and I checked every valve, union, etc. from skimmer to pump inlet with no visible signs of a leak. Each connection was sprayed with a soap solution in an attempt to see if any air was finding its way into the line on the suction side; nothing was detected. The pump basket lid is not cracked and the O ring has been lubed and I have also checked pump drain plug (O ring is fine and lubed). I tried the plastic wrap method around the pump inlet union and shaving cream trick, no discernible water or air leaks.

The Hayward 2 speed 1HP pump is brand new (model SP15922S)
The Hayward Sand filter (300# Model S244T) I purchased used off of Craigslist
.

Last night at around 9pm, I switched the pump from filter mode to recirculate and ran the pump on high for about 5 minutes. BINGO - all bubbles in pump basket went away within 5 minutes. I turned the pump off, went to bed, and this morning at 7am returned to pump with the basket completely full with no air bubbles.

So, why cant' my pump get rid of the air bubbles in filter mode? Is there a "rebuild kit" available for the multi-port valve where I can replace O rings, etc. if that is the problem? Is the multiport valve the problem?

FYI - on low speed, I get a sand filter pressure reading of 4 psi; on high it reads 18 psi. All of the sand in filter is brand new and I ran the filter to waste, and then rinsed before running and filter mode (wanted to get any PVC shaving out of of the lines b4 running in filter mode). The pool was filled with "city water" (i.e. same water that supplies my house),

Any insight into the above issue would be greatly appreciated.

Thanks,
Greg
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Greg, while we typically identify bubbles to a suction side leak, you appear to have done your homework. But I will also say that your filter PSI increase is reminiscent of an algae issue. Just to confirm, can you post a full set of test results from your TF-100 or Taylor K-2006?

Now you may ask what does that matter? Well, if we assume there is no suction side leak, and that the bubbles appear only on filter, it means there is some significant water restriction happening. My pump basket water level drops when my cartridge filter is getting dirty, so yours may be telling you the same thing. For example, does it help reduce the bubbles right after backwashing? That could mean organics are being purged which helps reduce water restriction until you run for a while and it clogs-up again.
 

GregN

Well-known member
Jun 18, 2015
50
Central NJ
Greg, while we typically identify bubbles to a suction side leak, you appear to have done your homework. But I will also say that your filter PSI increase is reminiscent of an algae issue. Just to confirm, can you post a full set of test results from your TF-100 or Taylor K-2006?

Now you may ask what does that matter? Well, if we assume there is no suction side leak, and that the bubbles appear only on filter, it means there is some significant water restriction happening. My pump basket water level drops when my cartridge filter is getting dirty, so yours may be telling you the same thing. For example, does it help reduce the bubbles right after backwashing? That could mean organics are being purged which helps reduce water restriction until you run for a while and it clogs-up again.
Sure, I will try to get some results. Posted in a day or twk
Greg, while we typically identify bubbles to a suction side leak, you appear to have done your homework. But I will also say that your filter PSI increase is reminiscent of an algae issue. Just to confirm, can you post a full set of test results from your TF-100 or Taylor K-2006?

Now you may ask what does that matter? Well, if we assume there is no suction side leak, and that the bubbles appear only on filter, it means there is some significant water restriction happening. My pump basket water level drops when my cartridge filter is getting dirty, so yours may be telling you the same thing. For example, does it help reduce the bubbles right after backwashing? That could mean organics are being purged which helps reduce water restriction until you run for a while and it clogs-up again.
Hi Pat - Thank you for your input; very much appreciated.
I will try to get a full set of test results tomorrow.

I'm not sure what you mean by "my filter PSI increase." The PSI reading with the pump on low (4psi) and high (18 psi) have been consistent with no increase since I started the pump/filter approx. 8 days ago. I would think that if I had an algae issue I would have seen an increase in the filter psi readings if the algae was restricting flow?
I will perform an overnight drop test and try to get more test results tomorrow and then post them.

Thanks again for your help with this issue.

Greg
 

GregN

Well-known member
Jun 18, 2015
50
Central NJ
Hi Texas Splash -

Here are test results from this morning:

Free chlorine 5ppm
pH - 7.4
TA 100
CYA 50 (this pool gets alot of sun)
Combined Chloramines = 0
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Well Greg, if your water is crystal clear, I don't see anything odd from your test results. They look good. So any reason for the air in the pump basket and returns would seem to be related to the equipment itself. The fact you only see air while in filter mode makes me wonder about two things - an undiscovered suction side leak, or somethig impeeding water flow through the filter. You can look at the spider gasket if you wish, but I'm not seeing how that would result in the bubbles. Usualy you'll see other indications of a bad gasket like water leaking to waste or mode not changing properly. You have my curiosity going for sure. :unsure:
 

GregN

Well-known member
Jun 18, 2015
50
Central NJ
Some more info to consider:

Bubbles in pump filter basket only appear after I open the lid to clean the pump basket. After putting the lid back on and starting the pump, the bubbles are present. If I run the pump on high speed with the sand filter in filter mode, the bubble remain. If I run the pump on high speed with sand filter in recirculate mode, the bubbles will completely dissipate after about 15 minutes. I can then return the pump to low speed and place valve in filter mode and no bubble appear and the pump can hold prime over night for 12 hours with pump shut off.

So it appears that I can only remove the bubbles with the pump on high and in recirculate mode, high speed with valve in filter mode won't make them go away.

If anything else comes to mind to help me further trouble shoot this issue, I'm all ears.
Thanks,
Greg
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,669
Pleasanton, CA
When the filter is in recirculate, there is less head loss and flow rates go up. The higher flow may be enough to evacuate the air bubbles while the lower flow rate in filter mode is not sufficient.

However, this would still be odd because under normal circumstances, the bubbles should still purge in filter mode. The filter pressure on high speed is a bit more than I would expect for that equipment setup. I would have expected something closer to 13 PSI. At 18 PSI, the pump is severely restricted and flow rate is very low.

Check all valve positions and make sure there is nothing that is partially closed off on the return side of the plumbing.
 
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GregN

Well-known member
Jun 18, 2015
50
Central NJ
Mas985 - thanks for input. All valves are wide open. This is a simple plumbing set up, with the pump and filter located about 10 feet from the skimmer and return jet location. The 18 psi reading at high speed and 4 psi reading at low speed are the SAME for both the filter and recirculate positions on multi port valve. Im thinking if it was something wrong with the filer laterals or the sand I would see different pressures in filter vs. recirculate modes? The sand filter was empty and I removed and inspected the filter laterals and they were in good condition.The 300# of sand I purchased new and was HTH pool sand.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,669
Pleasanton, CA
What is the size of the eyeball in the pool return? Is there only one return?

I suspect the extra head loss is post filter.
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,669
Pleasanton, CA
Ok, using the exact layout you have, I would expect a little over 16 PSI at the filter which is close to what you are getting. You may have a bit more head loss than what the equipment would indicated which could be due to almost anything.

Have you backwashed the filter? Might be worth a try to see if has any impact. Also remove the pump basket and make sure nothing is stuck inside the pump impeller inlet.
 

GregN

Well-known member
Jun 18, 2015
50
Central NJ
I backwashed yesterday, water looked pretty clean at discharge hose.... No effect on psi readings.

Should I stick with the 1" eye?
 

mas985

TFP Expert
LifeTime Supporter
May 3, 2007
12,669
Pleasanton, CA
See if the pump will prime in filter mode now.

The large eyeball increases the flow rate so it might prime now in filter mode.
 

GregN

Well-known member
Jun 18, 2015
50
Central NJ
See if the pump will prime in filter mode now.

The large eyeball increases the flow rate so it might prime now in filter mode.
😊😊 The pump basket cleared itself of all bubles, in filter mode, w 1" EYEBALL, with pump on high speed, in about 6 minutes. Thank so much for your help.

Any major mistakes w my plumbing set up? I probably won't bury lines this season?
GREG