preventing a siphon after pump shuts off?

[Hundredproof]

well just curious how you accomplish this when your res is taller (higher) than your garden. i found an air breaker that may work but they are used to prevent flow back to the source. any ideas? i know ive seen references to this issue before but im not finding what i need.

thanks in advance.

 

[HairlessCaveApe]

You just need a check valve.

 

[flux]

In your res, near the top of your feed pipe, place a 1/4" elbow connector, leave the end exposed. Some water should some out the 1/4" connector when your pumps are turned on so make sure all this water will go back ot the res. When you turn the pumps off the 1/4" should allow air into the pipe to prevent any siphon. its simple but works well.

 

[Hundredproof]

i like it flux, thanks alot man.

as for the check valve im not trying to prevent flow in the wrong direction, rather trying to break the siphon effect.

 

[Tony Aroma]

See my response in this thread.

 

[smurfin'herb]

i simply jus raise the hose coming from the res higher than the rez.

 

[hoosierdaddy]

Check valves are often included in some air stone set-ups. The check valve is used to stop the siphon effect. You could get one at PetSmart for about a dollar.

 

[Bozo]

I use a 44 gal brute trash can for a rez I use a different type manifold but same idea as yers
I run one line back to rez, just like flux.Even that will try to siphon off if i fill it tooo high ( I think it is combination of water level too high and water pressure from rez being so full) A second anti siphon tube might help I just dont fill it up so high
I found this problem the hard way had been putting like 20 gals in for weeks after getting 44 gal can .Then I left town for a week and wanted to fill it to top ,thats when i learned
Hoosier if I'm not mistaken those are just one way valves .I think those would make it worse because it wouldnt let air back into the dripper lines to help break siphon.
I had an idea for the use of a check valve to do this but never tried .I was going to T my pump hose and have an end in rez above waterline with a check valve on it ,1/2 inch should let a ton of air into line to break siphon,but will the air sucking back be strong enough to open check valve .I wasnt sure still not GL

 

[TokeItUp420]

For the Ebb-N-Grow system, they have drilled a VERY small hole in the elbow fitting. Yes a very SMALL amount of water escapes the hole when the rez is filling the system but when the pump stops then it releases the pressure and you don't have that siphoning effect. Not sure if I explained that well but hopefully you get the picture.



Peace...
Toke

 

[BlindDate]

Like this: Note the vent (just like Flux said). This is my version of a "Multi-flow Ebb & Flow system" without having to use that stupid unnecessary controller unit that everyone thinks they need to build. When I showed people how simple it was they got pissed off at me.

 

[badugi]

BlindDate, thanks for the illustration.

Can you please tell me a little more about "direct drive" pumps, what common brand(s) they're sold under, and how they're different than typical magnetic pumps that utilizes a magnetic shaft with impeller? (Like ECOPlus submersibles, for instance.)

How bad is it to run typical magnetic pumps (like ECOPlus) dry, and how long is too long?

 

[BlindDate]

The reason that I recommend a direct drive pump is because when that controller bucket empties, the pump will need to run dry for a while. A direct drive pump has it's impeller connected to the motor via a sealed shaft. A Mag drive pump impeller sort of floats inside a magnetic field and if running dry may hit the walls of the magnet since it is not securely supported on a strong shaft. A good direct drive pump for Hydro and ponds and such can be had at Home Depot under the "Beckett" brand.

As for how long a Mag pump can run dry? Well, if the impeller stays balanced, a long time. If it does not stay balanced, only seconds.

 

[badugi]

Awesome information. I wasn't aware of this. Do I look in the pond section or the plumbing sump pump section?

 

[JohnnyToke]

Check valves are often included in some air stone set-ups. The check valve is used to stop the siphon effect. You could get one at PetSmart for about a dollar.

my problem is the check valves ive tried from petsmart / walmart etc severely slow air flow. I get 10 times the air bubbles with no check valve verses using the petsmart / walmart ones. right now, im not using any but need to be. does any one make a check valve that does not inhibit airflow to a crawl?

I use a large 60l pondmaster pond pump with a 12 site gang valve. I got lots of airflow and need it to drive my 4" disc diffusers.

regards,
JT

 

[badugi]

Most air check valves are based on a spring, and will obviously inhibit airflow since a portion of the energy is spent on compressing the spring.

 

[BlindDate]

Can't you just keep your air pump or the tubing higher than the water level?

I really can't see how water can get into an air line and run back to the pump. You would almost have to try to do it.