Bean Animal issues

[derek_SR]

I built a fairly standard bean animal style drain in an external overflow box. Pretty much identical to this, with a tall/open emergency drain (left), a secondary drain with an upside down elbow, and a primary drain with an upside down elbow:

On mine, water comes in via the weir across the top which is a little ways above where I have the secondary drain positioned. The problem I am having is that every time I start the tank up, a siphon won't naturally form on the primary - water will rise to the secondary, start a siphon there, suck a bunch of water down and the water level falls back down, then rises again and the process repeats. After 5-6 times, a siphon finally forms in the primary drain and it stabilizes and quiets.

Does anyone know why this is happening? For whatever reason, the siphon doesn't want to start naturally in the primary - like there's air trapped that needs to get pushed out after a bunch of these cycles. Would cutting the elbow off and just having a low, open standpipe for the primary drain fix it? Any other issues with doing that? I'm honestly not even sure why there's an elbow on the primary, I just copied the most common bean animal designs...

 

[Patio]

Would cutting the elbow off and just having a low, open standpipe for the primary drain fix it?

I think so. This is how IM tank's BA drains are setup, no elbow. IM does not use an elbow on the secondary either.

 

[derek_SR]

Thanks! Good to know - I'll just cut off the elbow.

 

[Srt4eric]

Your secondary looks slightly high also

 

[derek_SR]

Your secondary looks slightly high also

it’s just a screenshot from the bean animal youtube video

though, i am curious what issues there are by having it too high?

 

[HankDean V]

My guess, if I’m understanding
The air won’t purge out of your down pipes causing back pressure issues,
Drill a small hole in the top of your elbows, this will let the air escape and the water flow through,
Also, is your drain pipe above the sump water level?

 

[RandyC]

Thanks! Good to know - I'll just cut off the elbow.

The elbow on the full siphon drain is likely for preventing a vortex from happening which could suck in air. In my experience, it doesn’t happen that often.

The elbow on the secondary drain is like any other durso and uses an airline out the top of the elbow to help silence the noise.

An elbow on the third drain in my opinion doesn’t matter honestly. That drain is last resort and hopefully isn’t ever used.

 

[Coral reefer]

My guess, if I’m understanding
The air won’t purge out of your down pipes causing back pressure issues,
Drill a small hole in the top of your elbows, this will let the air escape and the water flow through,
Also, is your drain pipe above the sump water level?

This. It can depend how far away your gate valve is and how long the drain line is and how many bends there might be how hard it is to get the air out

 

[RandyC]

This. It can depend how far away your gate valve is and how long the drain line is and how many ends there might be how hard it is to get the air out

Did you mount your gate valve horizontally by any chance on your full siphon? Or have long horizontal pipe runs that aren’t completely level on your full siphon?

 

[derek_SR]

My guess, if I’m understanding
The air won’t purge out of your down pipes causing back pressure issues,
Drill a small hole in the top of your elbows, this will let the air escape and the water flow through,
Also, is your drain pipe above the sump water level?

This makes a lot of sense - I'll try drilling a small hole in the primary elbow and see if that helps before replacing it. What do you mean by "is your drain pipe above the sump water level" ? It drains below the sump water level - I thought only the emergency drain was meant to drop above the water level to be noisy, or am i misunderstanding?

Did you mount your gate valve horizontally by any chance on your full siphon? Or have long horizontal pipe runs that aren’t completely level on your full siphon?

The gate valve is mounted vertically. There is a short run of downhill pipe after the gate valve and before the filter roll. Nothing horizontal or uphill.

 

[derek_SR]

Drilled the small hole in the primary elbow (mimics the one in the secondary drain) and the problem is gone, everything works perfect and silent now on the first startup! Thanks @HankDean V - saved me a bunch of time and hassle. I would have had to dismantle and replumb that entire bulkhead to get that elbow gone.

 

[Patio]

Good to hear!

I would have had to dismantle and replumb that entire bulkhead to get that elbow gone.

You must have glued the internal overflow plumbing inside the overflow box. I just go with press fit, figuring it can't leak. I do glue the external box plumbing though for sure.

 

[derek_SR]

Good to hear!



You must have glued the internal overflow plumbing inside the overflow box. I just go with press fit, figuring it can't leak. I do glue the external box plumbing though for sure.

I did - and I regret it. I think it would have been smart to just press fit them, a little leak around that elbow would be irrelevant anyway! You could technically even press fit the downpipe into the bulkhead (on the overflow side) for even more flexibility.

 

[RandyC]

I did - and I regret it. I think it would have been smart to just press fit them, a little leak around that elbow would be irrelevant anyway! You could technically even press fit the downpipe into the bulkhead (on the overflow side) for even more flexibility.

I’ve never glued anything inside an overflow box. Even if it leaks, the only concern is when the pumps stops, that it will leak the amount that’s left in the overflow box, which shouldn’t be enough to overflow the sump unless there was very poor planning on sump size - Even an internal overflow box.