Bean Animal tuning help

[leahfiish]

I need some help with tubing and finishing setup of my bean animal drains.
I have a 16" modular marine overflow on a 120g tank. The 3 drains use 1" plumbing and my return pump is rated for about 1321gph. I have about a 2ft vertical rise and 1 90° elbow, and 3/4" plumbing so I shouldnt be losing much gph (not sure if this is relevant). I am having trouble figuring out how to do the plumbing in the box. I have the main siphon in the middle with a gate valve and I was just using the bulkhead with no standpipe. The right is the emergency drain and has a piece of pvc that goes almost to the top of the box. The left is the open channel. I'm not sure what to put on this in the overflow box. This is where I'm most confused. Do I need a downturned elbow? What height should it be? I have just a single elbow on it right now and clearly something is wrong.
I've attached pictures of what I currently have.

 

[madweazl]

Run mine as pictured below. Main is center, secondary right, and emergency left. Has worked extremely well for the past 20 months.

 

[Breadman03]

The challenge with those relatively shallow external boxes is that it is fairly easy for a vortex to form and suck some air. You might need to swap for downturned elbows. the open channel line should have some sort of air venting, such as the fitting you see on @madweazl's plumbing. That allows air to enter the open channel, yet becomes a full siphon if water reaches that level and quickly drains the excess.

 

[leahfiish]

@madweazl What is the height difference between the secondary and emergency?

 

[madweazl]

@madweazl What is the height difference between the secondary and emergency?

Zero between the primary and secondary and the top of the emergency channel is one inch above water level (approximately 1/2" above the fittings).

 

[leahfiish]

I'm going to work on this a little bit more today but I hope I didn't mess everything up by making the main siphon the middle drain. I'm worried I won't be able to fit the pipes in the box properly. For now I put a taller elbow on the secondary and it helps significantly but I still have a lot of bubbles coming through.

 

[madweazl]

If a lot of bubble are coming through, you need to open the primary channel some more. I wouldn't bother raising the secondary channel as that has no bearing on the bubbles.

 

[ca1ore]

There are many ways to acceptably configure these drains. With my MM, I have the main siphon as just a bulkhead in the bottom of the box with a strainer installed. The emergency is a simple standpipe with opening about 1 1/2" below the top rim of the external box. The secondary/open channel uses a U pipe with vent hole with the top curve of the U slightly below the rim of the emergency standpipe. This ensures that the level of the water in the external box is high enough to prevent a vortex on the siphon and that I don't hear splashing sounds from the internal skim box. Keeping the secondary slightly lower than the emergency means it can kick into siphon mode before engaging the emergency.

 

[leahfiish]

The bubbles are mainly coming through the secondary I believe.

 

[Breadman03]

If they are coming through the secondary, very (very) slightly open up the siphon and walk away for a couple minutes. You should note a reduction in bubbles. Repeat as needed. If you start to get bubbles through your siphon, close it a little.

 

[leahfiish]

I thought I had this managed and then I turned off my return pump for maintenance and since I've turned it back on there's so much gurgling and air in the secondary despite adjusting the gate valve.

 

[Breadman03]

Very slight adjustments will be your friend. It was easy when I was running higher turnover in my tank, but I recently changed things around and have less turnover. It takes longer for the air to fully purge from my siphon line since there is less flow, but it clears within about 3-4 minutes.

 

[drtrash]

Whats the purpose of downturned elbows? Mine are all open pipe with zero noise and bubbles

 

[Breadman03]

Whats the purpose of downturned elbows? Mine are all open pipe with zero noise and bubbles

Primarily to prevent sucking air.

 

[leahfiish]

Here's a crude drawing of my overflow box
So the middle drain ("1") has the gate valve, and the left ("2") is the one that's been getting the air.
So if 2 is getting air doesn't that mean I need to raise the water level in the box by closing the valve?

 

[tripdad]

Try this fix for the primary line. Make a mark at water level in the sump on the pipe where it dumps from the main drain, in sock or out, doesnt matter. Then drill a 3/16 hole approximately 1/2" above this water level. This allows trapped air to escape and re-establishes full siphon easily after shut off.

 

[KJAG]

You don’t even need a valve on your siphon, period. If you have one, I would run it wide open and adjust the flow/standpipes via a gate on your return. Also ensure your standpipes terminate below the waterline no more than about an inch. Not sure how you’re currently operating it, but in short the siphon should be wide open and any flow variations through the standpipes should be accomplished with your valve on the return output

 

[MaddyP]

Run mine as pictured below. Main is center, secondary right, and emergency left. Has worked extremely well for the past 20 months.

I run mine like this as well, works perfectly.

 

[leahfiish]

I think I will try to replicate that tonight.

 

[madweazl]

You don’t even need a valve on your siphon, period. If you have one, I would run it wide open and adjust the flow/standpipes via a gate on your return. Also ensure your standpipes terminate below the waterline no more than about an inch. Not sure how you’re currently operating it, but in short the siphon should be wide open and any flow variations through the standpipes should be accomplished with your valve on the return output

If your drain lines flow more than your return pump is capable of flowing, how do you maintain siphon (the answer is, you cant)? While your method may work for you, beananimal designed it to have a valve on the primary drain for a reason.

@leahfiish, it sounds like your lines just arent purging after they start back up. The biggest cause is typically having the return lines submerged too far below the surface of the water in the sump. A very short length typically purges much faster (mine are about 3/4" below the water level in the sump). If your sketch is fairly accurate, there could be an issue with the primary and secondary drains fighting for the same water if the secondary is actually over the primary. Perhaps this is causing some turbulence that allows more air into the system. If that is true, separating them to something like the image I attached may help.