Suction Leak - Do You Have One? Try a Big Straw!

[JoyfulNoise]

I really think it’s a variable speed pump thing. I’m not in anyway a hydraulics expert (I’ll leave that to @mas985 and @JamesW ) but it has something to do with low pump speeds and where the pump is positioned relative to the water line. You can spend all day slathering silicone on every joint and seal and the bubbles will still show up.

All I know is I don’t have a leak in the pump because if I did the strainer pot would drain back into the pool. When the pump is off, there’s a small volume of air at the top of the lid and the level of water inside the pump pot never changes over the night time period when the pump is off (8 hours).

Just ignore as best you can. And if the voices in your head tell you to do weird things just put your fingers in your ears and run around screaming with your eyes closed … they eventually stop.

 

[mas985]

Outgassing of the water will occur under lower than atmospheric pressures which occur in a pump basket. On lower speeds, this outgassing can accumulate in the pump basket over a long period of time but it is usually much slower than what a true air leak would be. On higher speeds, there is enough flow rate to purge the air out of the pump basket.

The difficulting is determining if it is outgassing versus a real leak. The main differentiator is the time for accumulation. Outgassing is very slow, actual air leaks tend to be much faster.

So the big question is how fast does the air build up in the pump basket? Is it measured in seconds, minutes, hours or days.

 

[Oly]

Program the pump to ramp up the rpms at the end and/or the beginning of each full run to remove most of the air.

 

[JamesW]

And if the voices in your head tell you to do weird things just put your fingers in your ears and run around screaming with your eyes closed … they eventually stop.

Wouldn't putting your fingers in your ears just trap the voices inside your head?

 

[JoyfulNoise]

Wouldn't putting your fingers in your ears just trap the voices inside your head?

That’s why you scream … to expel the voices … geez, do I have to explain everything (yes, yes you do because they’ll never understand us … )

 

[PoolStored]

PSA. Not attacking anyone, but something pool owners need to be aware of...ANSI creates a standard for return lines to pools. While this thread is not pool return line related, still applicable...need to protect life and limb.

Too often, “well, this works.” - In a world of litigation, following the standard care is the best way to prevent an expensive lawsuit in the event of an accident.

https://issuu.com/.../apsp-16_2017_includes_provisional...

At bare minimum; any pipe over 1” requires a return fitting to prevent a person from sticking their arm into a pipe. A small child can easily lodge their arm into 1.5” pvc leading to potential entrapment and drowning. With a suction side connection, this is even more important.

While it may be tempting to short-cut with Google; there are standards organizations that exist and regulate swimming pools.

@Texas Splash (I honor your expertise) is no neophyte and I'm sure has taken the right precautions to protect life. Others, please create a safe testing environment, and certainly don't create an ongoing open pipe danger to swimmers. Even if it solves a suction side leak.

Swim safe.

 

[Texas Splash]

Since several folks pointed out concerns about risk to an exposed suction line, I updated my first post. Common sense really, but if this becomes more of an issue for TFP I'll just deleted the thread.

 

[Newdude]

Common sense really

Of course. We all inherently understand the risks, being enthusiasts as we are. If a newb was to stumble across this down the road, they may not understand the possibilities or why their system had failsafes and safety measures in the first place.

But now we covered them so they will too.

 

[dleonard1122]

I'm glad I'm not the only one who went a little paranoid about trying to find a leak. I like your troubleshooting method, certainly better than digging up and replacing a perfectly good plumbing.

At this point, I've just scheduled my pump to run at 1250 RPMs for 23:45 and 2500 RPMs for the remaining :15 minutes to do a daily purge of any air in the system.

 

[PoolStored]

At this point, I've just scheduled my pump to run at 1250 RPMs for 23:45 and 2500 RPMs for the remaining :15 minutes to do a daily purge of any air in the system.

Yeah, I did the deep dive on the suction side myself. ^^This is the same conclusion I came to and have been running this way for a couple years. Good to Go!

 

[drsipe]

I'm sure you already looked at this, but debris in the impeller can reduce pump suction, and reduced suction can cause low flow and bubbles will accumulate in the pot.

 

[JoyfulNoise]

I, for one, think what @Texas Splash did was amazing! Honestly, it’s obvious it’s a temporary test setup. You all are OCD’ing way too much on the suction hazard … Good Job Pat