Playing with overflow plumbing

[rseleri]

Hi,
Would love to understand what the heck im doing wrong and perhaps why im dumb for thinking it should work .



Ok so I hope the image is clear. Essentially ive created a U shape from pvc attached with pvc cement and in a good amount to prevent air escape. I also siliconed an air valve to the top of the pvc and tubed it to a venturi intake in my filter. I can see it creates some kind of suction but i can get it to overflow from the tank to the bucket with a siphon.

Ill explain where im heading with this. Id like to create a siphon directly from
The tank to the sump with any overflow box. Im aware of the disadvantages of it.

In theory, i dont understand why this shouldnt work but maybe im missing something.
Could it be that i need more air suction power due to long pvc pipes? Do i need to somehow fill the pipe with water first? (Is so, how ?)

Looking forward to get more clever

 

[KrisReef]

1st, It can work and it will be easier with a shorter u tube.

The air valve, I have seen a set up similar where you are supposed to put a suction tube of airline on the check valve and suck on it (no other way to say that) until all the air is out so the tube will fill and the siphon will start to flow. To make the sucking thing work you have to have water in the bucket and in the tank, but notice that you are going to have to pull all the air out of the tube thru an airline straw and the effort that takes may be difficult for people with small lung capacities?

Plastic PVC and Airvalves are not easy to seal using silicone sealant. Any tiny leak is going to make this not workable.

As far as other ways to fill the pipe, turn the pipe over and fill the u tube until water is spilling out of the short end. Slide a pvc cap on the leaking end and continue filling until the u tube is full. Cap the long end, ,invert and then you will start siphoning and the bucket will be filled and overflowing unless you have a return pump on it.

If the silicone seal is leaking the siphon will break.