Air pump overheating? Need an engineer to explain the physics

[texmaster]

Hi Folks,

So I have a system for air that goes to a koi toilet diffuser and to a large helix waterfall. I've had an alita al 100 air pump that worked without incident for 6 years before it failed. I went with a different pump this time to save some money and after 3 months it failed so I turned it in for warranty work. Then I get grilled about my setup and they are claiming I'm "restricting" the airflow and that the air pump I bought (also a 100) is just too powerful and its overheating.

So my question is if I have a large 1inch pipe for air that branches off to my diffuser and I have a valve to adjust the flow which I favor the waterfall and provide a small amount of air for the diffuser how does that make it all the way back to the air pump itself and how does it restrict it in any way if it has 2 exit points?

I'm really confused about this logic of theirs especially since my first pump worked without incident for 6 years.

 

[Stephen Noble]

I am going to guess is a back pressure issue based on experience with aquariums and small ponds. I always have a relief valve vent off the extra pressure. I would hook up whatever pump you have now and run your pond/waterfall and see if there is extra pressure in the line. If so, vent it off to prevent back pressure. Edit: I should have asked an obvious question. Amazing what the brain does while drinking coffee sitting by a pond! Have you checked to ensure there is not an obstruction in the lines?

 

[texmaster]

I am going to guess is a back pressure issue based on experience with aquariums and small ponds. I always have a relief valve vent off the extra pressure. I would hook up whatever pump you have now and run your pond/waterfall and see if there is extra pressure in the line. If so, vent it off to prevent back pressure. Edit: I should have asked an obvious question. Amazing what the brain does while drinking coffee sitting by a pond! Have you checked to ensure there is not an obstruction in the lines?

I haven't yet because I dont have a working pump to test but I highly doubt it.

What I cant figure out is how there could be any back pressure if the air has 2 different exit points

 

[JRS]

What I cant figure out is how there could be any back pressure if the air has 2 different exit points

Theoretically possible, depends on the volume of your pump and the restriction of your diffusers/outlets. Did they provide any details on what you should have done different based on their pump size? Or perhaps, that is their go to answer for problems? Did they confirm a ripped diaphragm?

This is the one that failed? https://www.pondusa.com/product/blue-diamond-et100-pond-air-pump/

 

[GBBUDD]

NITTO NITTO AND MORE NITTO. they are a piston driven air pump not a diaphragm and last three times as long. i have a 80 and a 120 on a rhino koi toilet but i do not run them all the time but it is the air pump of choice for the raised koi boys

 

[texmaster]

Theoretically possible, depends on the volume of your pump and the restriction of your diffusers/outlets. Did they provide any details on what you should have done different based on their pump size? Or perhaps, that is their go to answer for problems? Did they confirm a ripped diaphragm?

This is the one that failed? https://www.pondusa.com/product/blue-diamond-et100-pond-air-pump/

I still have the pump so they never confirmed anything and my old alita al-100 ran for 6 years on the same setup.

They claim if I had some kind of diffuser to release the backup pressure it would last longer and when I explained I never needed that on my alita they said "well this isn't an alita"

And the exit port on my waterfall is a wide open 1/2 pipe. The koi toilet I dont know but I divert 90% of the air to the waterfall.

 

[JRS]

I missed that, I would agree with an open pipe, restriction/back pressure is not the issue, yet that was their explanation for failure. Sounds like a canned response since it can happen. I would contact tech support at another manufacturer, to explore the tech details of that type of pump if you are looking to counter their refusal to warranty, since I am no expert on these.

These guys have a site with good info: https://www.hiblow-usa.com/applications-guide/pond-aquaculture/

 

[GBBUDD]

I haven't yet because I dont have a working pump to test but I highly doubt it.

What I cant figure out is how there could be any back pressure if the air has 2 different exit points

Pushing water out of the tube and if it's going down in the water then you have partial atmospheric pressure. Place a garden hose a foot below the surface of the water then blow through it and see how much back pressure there is.

 

[texmaster]

Pushing water out of the tube and if it's going down in the water then you have partial atmospheric pressure. Place a garden hose a foot below the surface of the water then blow through it and see how much back pressure there is.

My new alita al 100 showed up and I've hooked it up and the air certainly looks free flowing without issue. I think this has to do with the maker of this pump because my last alita lasted about 5 years no issues.

 

[GBBUDD]

Hope it works out for you. I only run the air pump in the winter now. I added a bakki shower a soft spot for me after having trickle filters in the past as when i was using them we were pioneering them in the salt water hobby back in the early 80's

 

[texmaster]

Hope it works out for you. I only run the air pump in the winter now. I added a bakki shower a soft spot for me after having trickle filters in the past as when i was using them we were pioneering them in the salt water hobby back in the early 80's

I really appreciate your advice.