Bubbles in pump strainer basket

eric99gt

0
LifeTime Supporter
Sep 14, 2009
191
Houston, TX
I'm having issues where I've had a ton of turbulence in my pump strainer basket. When I was still using a pool service he mentioned that this was normal for this type of pump. I've been messing around with it and I notice that when I divert water away from the skimmers and to the main drain the turbulence in the pump decreases greatly. At the advice of another thread someone mentioned the weirs may be the culprit. I've looked at my weirs and I've even held them down yet the pump still has a ton of turbulence unless I close off the skimmers. Any thoughts?
 
It's a 2 hp Hayward Northstar Pump. Water level is at its peak. No vortex with the weir in its normal position or the weir held down. I'm guessing the piping is 2" pvc. Picture may help

PA110044.jpg
 
As noted above. At the inlet there's a valve adjusting where the pump is pulling water from. If left in a position where it's fully open to both the main drain and the skimmer I get a ton of turbulence. Once I adjust to block the skimmer line off most of the turbulence goes away
 
This plumbing is typical of a pool/spa combo with the actuated valve in the pool suction position. It also appears you have a single skimmer and drain in the pool.

If the above is correct, then

The valve controlling those sources appears to be off, as evidenced by the handle pointing and buried slightly in the ground. Turn that handle 180 degrees so the handle is up.

Scott
 
There's 2 skimmers and 2 drains in the pool. Pointing it up would block all incoming flow to the pump and as such the valve does not turn in that direction. Maybe it's the picture but the handle is pointing up. As it's currently set I would think that both lines (drains and skimmers) are completely open to the pump. Turning it 180 I think would block off all flow....Unless I'm dumb which could be the case.
 
Really hard to tell, Eric, but that looks like 1 1/2" plumbing to me. That's pretty tough on a 2 HP pump. By allowing more water flow you are helping the pump draw easier; still not optimal for that big of a pump, but helpful!
 
It very well could be. It was just a guess at this time. I'll measure when I get home. So what you're thinking is that the pump can not pull enough liquid through the small pipe and thus results in the turbulence within the basket? That may make sense as if it's switched over to just the main drain the increased head pressure may allow for better flow.
 
On a 2 HP pump, I would really like to see 3" pipe, so you will be "undersized" with anything less, in my opinion. But, you can "help" the pump by doing anything you can to get it more water. It will always "neck down" at the front of the pump, but if you can keep multiple pipes feeding as far as possible, that will help.

Pipe has a "flow rate" associated with diameter. Big pumps need bigger pipes to supply proper flow. Length of run, 90 degree fittings, solar, etc. all impact pump performance, both coming and going. Someday, if I were you, I would switch out that 2 HP pump (good chance it is too big for your pool anyway!). I didn't look ( :oops: ), but how many gallons is your pool? A smaller (or multi-speed/variable speed) pump would be good to consider for when you need to replace what you have.
 

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Ya I've been doing a bit of reading on pump performance since you mentioned it and it very well looks like the pump is oversized. I don't think there's anything else I can do to increase flow right now though as all the intake lines to the pool are open. I have the pool estimated to be about 15k gallons. As for replacement, any problem on just waiting for this one to die due to age/use? Thanks for the help all
 
eric99gt said:
Ya I've been doing a bit of reading on pump performance since you mentioned it and it very well looks like the pump is oversized. I don't think there's anything else I can do to increase flow right now though as all the intake lines to the pool are open. I have the pool estimated to be about 15k gallons. As for replacement, any problem on just waiting for this one to die due to age/use? Thanks for the help all

Wow, you could be using a 3/4 HP pump (and saving a lot of electrical dollars) on your pool! Somebody wasn't thinking of your wallet when they put that pump in!

No worries on running it until it dies, except for the electric costs. The good news is that you have good sized pipe for the smaller pump, and a lot of options for more efficient pumps when you do need to go that route. For now, you'll just have to keep pushing 4 lanes of freeway traffic into one lane (is that a good analogy for the water?!).
 
Thanks Bruce. It came with the house when I bought it and it looks as though they bought in to all the high end stuff. Ozonator, pumps, controls, etc. They also put in an exact duplica of the pump just to run the waterfall feature.
 
I noticed it all looked like nice stuff, and lots of it! Nothing wrong with that!

Now, quit worrying about this stuff and go use that pool :goodjob: Isn't it hot in Texas, and isn't that where you really should be instead of on the computer :lol: :lol:
 
Holy thread revival. So it looks like the issue is still alive and it's not the oversized pump that's causing the bubbles. Had the pump replaced on Monday and now with the new Pentair VS pump I can drop it down to much lower flow. Well it didn't help the issue. There's still significant bubbles in the strainer basket and if I run the pump at very low speeds (1000 rpm) the pump strainer begins to fill with air and empty. I need to bump it up to a higher flow (1900 rpm) to keep the water level in the pump sufficient.

So with that said I guess this all points back to a suction side air leak. What are my next steps here? I've already addressed all the typical sources of air leaks such as the water level, weirs, valves. We know it's not a leak at the pump as the pump was replaced and the issue existed both with the old and the new pump. As mentioned in the beginning when I only pull water from the main drain and not the skimmers the bubbles greatly diminish/eliminate, so this may help narrow down the source. I guess I have two options here:

1. Involve a leak detection company
2. Ignore it (not sure of the long term impact of this, inefficient operation of pump? something worse?)

Any thoughts? Also video for visual
http://smg.photobucket.com/user/lindros163/media/pool%20pump.mp4.html?filters[user]=2913232&filters[recent]=1&sort=1&o=0
 
That stinks. :grrrr: And you're right .. this was quite a thread revival. :slidehalo: I would be inclined to believe their is some sort of compromise along the skimmer suction line(s). Ignoring it could be problematic for your new pump and defeat the purpose of having a VS pump so you can use the low RPMs. Sure, you could solicit the help of a company to do a leak check. Or, if you feel real energetic, start trenching/digging. Uhg. :( As a final thought if not mentioned or tried before, some TFP'ers have simply ran a temporary above-ground pipe from the pump directly to the water just to see if it did indeed rule-out the underground line. Just a thought.
 
I'm liking the temporary line idea. I would hate to start trenching and not be 100% that this is a suction side leak. I'm almost positive that it is but any other tests to be sure are comforting before I get out the shovel lol. I'm also wondering now if this has always contributed to my pH rising faster than I would expect. I have a swcg but it always rose more than I thought it should. Thanks Texas
 
5 years later and it's finally solved! $325 lighter in the pocketbook but it's worth it....Details details

So I went ahead and pieced together the temporary line as suggested. Sure enough the air bubbles went away. Ok I am now positive I have a suction side air leak but am really not feeling the get out a shovel and dig method in the texas heat (only 90 today). I broke down and called a leak detection company. Now mind you I have had a leak detection company out previously around 2010 but the main issue then was a small leak in shell so they didn't dig too deep in to the air suction issue.

This time around I explained my dilemma quite thoroughly and they began to work. They pressured up the suction lines and i'm standing there eagerly waiting for the pressure to start dropping...nothing. They were getting doubtful that they would be able to find any leaks. But since they could see the issue and I showed them the temporary pipe hooked up produced no bubbles (video), they let the pressure sit on the pipe a little longer than they normally do. Then bam it appeared.

Water had made it's way back up in to the stupid old defunct ultrapure automatic water cleaner you can see pictured in the first post. You could see a steady drip of water from the bottom. It was sucking air from inside this **** thing. I pulled off the hose and threw some shaving cream on there but it wasn't sucking anything so I was still slightly hesitant that this was the issue. Since the thing hasn't worked since I bought the house I took out a hacksaw and capped that pipe off...too easy. Sure enough this solved the problem. No more bubbles in the pump strainer and my pump can work nice and efficiently.

I'm really hoping this addresses some of my pH rise too. I've became great friends with the nice lady at the local pool store as I'm always in there buying acid. Always thought it rose quickly but just attributed it to the swg. Watching it today, and now having no bubbles come out the returns, I think I will have some success here as well.

The lesson learned here....ditch the ozonator lol
 

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