Bean Animal dimension questions

[jgvergo]

I'm about to plumb in my Bean Animal system. I have an interior, coast to coast overflow box with the 4 holes already drilled. It is an 85 gallon tank plumbed with 1 inch PVC, so I plan to have about 1000 gph flow through the sump. The teeth in the overflow are about 2 inches tall. My questions are:

1) What is the difference in heights of the full siphon, the open channel and the emergency standpipes?
2) Also how far should each be from the top of the tank (or the bottom of the overflow)?

 

[Rybren]

My holes are all even with each other. However, in retrospect, I should have made the full siphon about 1/2 to 1" lower than the others. It would make start up just a tad easier.

The open end of the siphon and OC elbows are about 3/4" above the bottom of the overflow box.

 

[keithp]

I have only built one but this is what worked for me. The overflow just has to be a little below the rim of the tank. I put it higher than the weir but still more than an inch below the rim. It must be higher than the other drains. It does not have to be higher than the weir.

The full siphon only requires an internal pipe with an inverted "U" bend if the flow is enough to cause a whirlpool sucking in air. Otherwise it can be at the bottom of the overflow box. There may be other reasons to add the bend but I don't know any. This one must be lower than the other drains.

The other low flow drain sets the water height in the weir box and should be set low enough to cause a short fall from the tank to weir box. Without the fall, surface skimming seems to be reduced. I originally cut them too long and got no effective surface skimming. 1/4" to 1/2" is probably enough but depends on overall size and flow rate.

I did not glue any of the internal pipes since there is no pressure and that has allowed the adjustments to improve it.

 

[Eckolancer]

My holes are all even with each other. However, in retrospect, I should have made the full siphon about 1/2 to 1" lower than the others. It would make start up just a tad easier.

The open end of the siphon and OC elbows are about 3/4" above the bottom of the overflow box.

This is how mine is. My emergency is same height as the teeth to the overflow box which is about 1/2" below rim of the tank.

 

[jgvergo]

Please bear with me. I'm a newb. I don't think I asked my question correctly, so this time I'm including a diagram. I have an interior overflow. The top of the overflow is 1 inch from the rim of the tank. The "teeth" (weir?) of the overflow are 2 inches tall and the top of the teeth is 1/4 inch from the top of the overflow. For a bean animal system, I always see a 90 degree elbow, pointed down, as the intake for the full siphon and open channel standpipes. I have sketched one of those standpipes and indicated "X" as the dimension I need to know. I need to know "X" for the full siphon and the open channel standpipes. (Guess what I'm doing today

 

[jgvergo]

I should also say that I want them to be as tall as possible so I can maximize my water volume in the tank.

 

[keithp]

I should also say that I want them to be as tall as possible so I can maximize my water volume in the tank.

The bottom of the horizontal part of the 90° bend is the important dimension. Both should have X>3.5, assuming the elbow extends down an inch below the horizontal. The extra 0.25 inch is for better skimming.

I believe the siphon starts quicker when it is an inch below the open drain (X=4.5). This means you don't need as much water over the return pump and restarting is quieter with less sump salt spray.

I dont think there is a perfect answer because flow rate, weir width, pipe size, and probably some other things can affect how it all functions. If you don't glue, you can adjust it once the tank is running.