Creating a bean from dual overflows...

[fishgate]

I just set up my 120 gallon tank (no overflows - I drilled it) with a Bean drain system. I really like this full siphon thing. So I am going to convert my 125 with dual weirs, 2 holes each.

My plan is to use hole 1 in weir 1 for the full siphon, hole 2 in weir 1 as the emergency, and hole 1 in weir 2 as the trickle drain. Then I will use hole 2, weir 2 as the return, but allow the return to come out near the bottom of the weir for water movement in the weir. Not sure this is going to work since I will have to put the emergency drain rather high to clear the weir and as to not drain the return water.

Anyone ever do this?

 

[jimmy_beaner]

I've read some posts about people doing it. From what I remember, if you do that, the weir with the trickle drain will have stagnant water (not enough flow to get "turn over" of the water that's deep in the weir). Most appear to solve that by connecting the weirs.

 

[fishgate]

I've read some posts about people doing it. From what I remember, if you do that, the weir with the trickle drain will have stagnant water (not enough flow to get "turn over" of the water that's deep in the weir). Most appear to solve that by connecting the weirs.

I think my design overcomes this limitation by having the return water discharge near the bottom of the 2nd weir. The 1st weir is the drain so that should have adequate circulation.

 

[jimmy_beaner]

Near the bottom on the inside of the weir? The problem isn't in the tank, the problem is the column of water inside the weir that will have very little movement. It can't have great movement with just the two pipes you've listed in weir 2 because one is the return pipe (so it is pumping water outside the weir) and the other is the "open" which can't have a lot of flow otherwise it won't be quiet. This means you have water trickling into the top of the weir and then draining down the open channel. The water deeper than that surface water never moves because there's nothing to give it flow to move.

 

[fishgate]

No - The return water going back to the tank will discharge at the bottom of the 2nd weir. So fill the weir and come out the top. That will create movement in Weir 2.

Weir 1 is the primary drain so that will be the same as it is now with the same movement as now (actually more since increased flow with full siphon).

 

[Mrramsey]

Just do a dual Herbie. The BeanAnimal is more than just the drain. It also employs the coast to coast overflow to maximize surface skimming of the tank.

 

[jimmy_beaner]

No - The return water going back to the tank will discharge at the bottom of the 2nd weir. So fill the weir and come out the top. That will create movement in Weir 2.

Weir 1 is the primary drain so that will be the same as it is now with the same movement as now (actually more since increased flow with full siphon).

If the return is at the bottom of weir 2, and you plan to have water also draining into weir 2 for the "open channel"... how do you plan on that working? It'll fill up from the return as well as drain from the open channel.

Maybe it's just me not understanding, but if you're filling up the inside of weir 2 and planning on that water leaving the weir, with tank water also coming into the weir to trickle into the open... that won't work. Water will only flow one way either into or out of the weir (because water works with gravity, the weir overflow height can't both be above and below tank water height).

 

[SGT_York]

The other issue is water height in the display.

The 2nd overflow with the trickle will have to be set higher than the weir or the trickle drain will be 50% of the water flow caused by the weir height and not a trickle. The only way to make this work is to raise the display tank water height over the weirs. This is further complicated by teeth in the overflow box itself they were never designed to handle more than 300 GPH each overflow.

Stated another way if the open channel is lower than the weir height any water going into the overflow will rush down your loud durso.

It's a bit hard to visualize but if you run a test you will see what I mean. Dual herbies is a much better method than a split overflow design. One herbie in each overflow with the return behind the tank.

 

[fishgate]

Yeah I can see this design is crap. OK I will look at dual Herbies and over the back returns.

 

[mr.maroonsalty]

I combine a bulkhead from each box with a tee syphoning straight from the bulkhead; there is no need for any other plumbing. In place of the adapter bulkhead in each box, new full size bulkheads are used for the backup drains. I adapt 1.5" pipe down to 1" bulkhead then back to 1.5. I believe about 2" of 1" will handle much more flow than 24-30" will, but let the fluid engineers figure that. I cut down my factory boxes mid way through the teeth so they handle more flow. Let water trickle in one backup and you are running bean style, keep them dry and you are running Herbie style. I find no need for anything other than a straight standpipe for backup drains. I run both dry; I like to hear what is going on with the syphon: if water gets low in the box, I get sound from there, same if water is over an em drain. Here's how I did it, if you want more pictures just let me know.
http://www.reefcentral.com/forums/showthread.php?t=2260230&highlight=dual+bulkhead

 

[Toddrtrex]

Yeah I can see this design is crap. OK I will look at dual Herbies and over the back returns.

I did that with my 210, and I am very pleased. Been running for about 2 months and after the first week I haven't adjusted the valves at all.

 

[EDJFA]

Yeah I can see this design is crap. OK I will look at dual Herbies and over the back returns.

I did exactly what you proposed and it works fine for me. I'm not convinced the lack of water movement in the overflow is a huge deal.

I do have gate valves on the drains to control them and to keep them from sucking air or putting too much water through the emergency drain. I do find it interesting that I can tell when the atmospheric pressure changes because I have to adjust the gate valves to compensate.

The setup is S-I-L-E-N-T. My tank is in my office and I don't yet have the stand skinned, so everything is still wide open. Sitting here, 10 feet or so from the tank, I can hear my skimmer running, but that's the only noise I get. Only once in a while, I think due to weather, I do get some water trickling into the emergency drain or the drain pipes draw some air, but a very minute turn on the gate valve stops it immediately.

I'd say go with it.