pump problems- LOW FLOW & BUBBLES

I recently bought a dual speed pump, 1 HP for a 18' round above ground...to work with a Hayward Perplex DE filter

My problem is....

Originally when I bought it the high speed worked fantastic and as quite honestly impressive. I vacuumed with it...perfection.

I started er' up last night to vacuum and low puts out a trickle (out of the return) and high works about as well as low used to. Also, air bubbles spit out of the return...AND the pumped works slow for 20-30 seconds spitting out air bubbles and then it's like a toilet bowl flush where everything rushes through and the return works/skimmer works completely normal. It works normal for maybe 5 seconds and back to low return water and low suckage.

Any ideas?!?!

Sounds like a suction side leak. Or, it could be a malfunctioning skimmer, allowing air to be sucked into the pump.

Suction side leaks can alternate between air killing suction, flow dropping, pump fulling priming, momentary full flow, and then . . . air sucked in, killing suction again.

Is there an easy way to fix? Besides maybe tightening the fittings...

My wife thought maybe it needed more DE in the filter but that doesnt sound right to me

What do i do if it's a malfunctioning skimmer?

As a rule, suction leaks aren't that hard to FIX, they are just hard to FIND.

Unfortunately, "hard to find" means, "hard to find for me!", with 30 years of pool experience. If you don't have a lot of DIY experience and understanding, it tends to mean "extremely hard to find" for you.

And, it's not the sort of thing I can help you do: suction leaks tend to be icky-picky things that get overlooked. I'll give you a list . . . but after that you're pretty much on your own.

1. If you are looking for a suction leak, you can rule out EVERYTHING on the pressure side, that is, downstream of the pump. (Including the filter!)

2. Suction leaks draw AIR into the piping; pressure leaks let WATER out of the piping. You need to keep this in mind.

3. Pumps change from suction side, just upstream of the impeller, to pressure side, just downstream of the impeller.

4. Places where I have found suction leaks include:
=> pump basket lid gaskets
=> cracked pump lids. (Cracks further down on the pump are PRESSURE leaks)
=> leaks at where pipe connects to the pump.
=> leaks at valves. (I've found leaks AROUND the valve STEM).
=> leaks at winterization drain plugs
=> leaks at any feeder or tubing that is on the SUCTION side of the pump.
=> leaks at a 'whirlpool' in the skimmer
=> leaks at a cracked skimmer.
=> leaks underground, in the piping (DISASTER!)

5. A leak like your may 'hiss' when the flow transitions from "full" to "bubbly, with little water".


. . . that's all that's coming to mind at the moment. Good luck!

PS. OVER-tightened fittings are ALSO a source of suction leaks: plastic cracks when over-tightened.

PPS. If you post pictures of your pool AND piping, something may 'jump out' at me or someone else here.

Great advice. My 10 yr old pool had a suction side leak at the valves just before the pump for the first time ever this year. Leak was pulling in air from the skimmer line when pump was on, but after hours of troubleshooting I finally noticed it dripped water when the pump was off. Super simple fix too as that coupling was just hand tightened!

Thanks to PoolDoc for that long list of possible leaky suction sites. This thread is very timely for me as I just got around to opening my 16x32 inground pool with Hayward DE pump/filter. The water was pretty murky, so I thought the filter was getting clogged causing the system to somehow draw in air that I could see in the pump basket after an hour or two of running. After turning off the pump and giving the filter a bit of a shake (or backwashing), the pump would nicely re-prime and run nicely, but just for another hour or two.

I just ordered a new gasket for the basket lid, since it's pretty old. I hope that's it.

I do have some cracked flexible tubing on the return that doesn't leak if I don't touch it, but I can't imagine that's part of my drop in pressure issue.

Are there any other tips in identifying where suction leaks may be coming from? It's no big deal to throw money at a $6 gasket that takes a couple minutes to replace, but blindly replacing parts is certainly not efficient.

Many thanks!