Quikskim is not skimming!

[bhargraves]

Hi Everybody,
Our PB installed A&A mfg Quikskim venturi skimmers (2) on our new pool. They are advertised as being able to skim very efficiently even with pumps at low speed.

Our problem: They are not skimming at all! There is almost no water going across the weir. The weir door basically stays upright instead of being drawn downward by the flow of water into the skimmer, mainly because there is no flow into the skimmer.

We have a Pentair Intelliflo pump, running at 1850 RPM typically (higher during Polaris cleaning cycle). Valves are completely open on each of the 2 skimmers, about 15% open on the spa return, and 75% open on the pool return valve.

Does anyone have any ideas why the skimmers would not be functioning properly?

Thanks,
Brian

 

[JasonLion]

The QuikSkim requires it's own return water supply to work correctly. That return line is supposed to have a valve on it. Perhaps that valve is closed? This line/valve is separate from the suction line from the skimmer to the pump inlet. Perhaps you have the return and suction valves for the skimmer mixed up?

Also, try closing the normal return valve more and see if that has any effect.

 

[bhargraves]

Each of the skimmers has its own return valve, and I've confirmed they are mapped correctly. Closing the pool return has a little effect, but not much. If I crank the pump up to full speed and close all other returns except the skimmers, I get decent skimmer action. But, this seems crazy. The QuikSkim YouTube videos claim they are running the pump on "low speed" (whatever that means), and it shows water pouring through the skimmer.

 

[JasonLion]

Looking at their diagram of how the skimmer works, it looks like you should be able to remove the skimmer basket and observe the venturi jet in action. You should be getting a strong jet of water coming out of the jet port. From there most of the water should proceed straight ahead directly into a pipe that comes out on the pool wall below the level of the skimmer. Either low jet pressure or a blockage of the pipe leading to the below water port could easily cause a problem.

 

[bhargraves]

There is a jet of water, but I'd classify it as pretty weak in both skimmers. I'm able to remove the jet nozzle in one of them to check for blockage, and there isn't any. The other nozzle is jammed an I can't unscrew it. The skimmer literature mentions 6-8 GPM going through the jets. I would expect at least that with the intelliflo 3050 vs running at 1850 for the returns and skimmers with valves set a shown in the picture.

One other issue I am seeing is the pump is losing prime every night. I'm not sure where the air is getting in. :/

 

[bhargraves]

Update. First off, it turns out we have Waterway venturi skimmers, and not A&A QuikSkims. Same concept, just a different manufacturer. Anyway, the guys re-worked the post-filter plumbing based on a drawing I gave them to add a heater bypass and optimize other plumbing and maximize efficiency. That showed a little, but not much, improvement in the skimmer action. But, it did fix the low flow issues on the IC60. Because of the skimmer issues still, I pressed further. At that point, the pool builder service guys started poking around in the skimmer itself. They removed a piece of PVC with a check flap that goes into the outlet of the skimmer. The venturi skimmers have a jet inlet nozzle, then a gap, then an outlet to create a venturi effect, which causes the skimming action. When he removed that outlet, the skimmer started working significantly better. They then reworked the outlet to remove the section of pipe with the flap, and inserted the remaining piece in the outlet. This allowed the skimmer to work pretty much as expected, even at low pump RPM. It appears that the flap on the outlet was blocking flow enough to inhibit the venturi action. I can now run the pump low (currently at 1600) and IC60 and the skimmers are both working.

 

[ColinBlake]

I was having a similar problem with my Venturi skimmer just not working as well as it should, and thanks to reply #6 I removed the inlet and output pipes from the skimmer and found the problem. A stone in the venturi nozzle almost completely blocking it.

 

[mercsburgh]

Hi, I came across this thread searching for a question I have on my venturi skimmer. I see in the pictures you posted that the lines to the Quik skimmer are 1 inch. Is that correct? Reading the installation instructions I think it calls for a 1 inch line. Just trying to make sure. My PB has installed two inch lines and I think its wrong. Thanks for the help.