questions on setting up bean like siphon overflow

[blurry]

I'm helping a friend setup a full siphon on his 240 gallon tank. the tank is drilled to accommodate two 1" drain lines and two 3/4" return lines.

The thought is to use one of the two 1" drain lines as a full siphon and the other as a durso overflow with a dual float switch as a safety. The siphon drain would be positioned a few inches down from the durso to provide some wiggle room. The siphon drain will have a 1" gate valve immediately below the tank. due to positioning of the tank and surroundings, the 3/4" return lines have to be used as return lines. both are needed as there is notably different flow rates to them as we are trying to minimize powerhead usage

The tank is run on a basement sump (about 13 feet down)

questions:
* what should the diameter of the siphon drain pipe below the tank be? should we maintain the 1" or go up to 1 1/4" or 1 1/2"?

* I'd like to use a threaded bulkhead inside the tank for the siphon, however this slightly reduces ID - any concern?

* for the siphon drain is there any reason not to use an open pipe pointed straight up with a strainer on it, or do we need to put a capped T with a slip 90 on there? I can't see why, but everyone seems to put a capped T with a 90 on.

* any other suggestions on how to best do this?

thanks for the help!

 

[Troylee]

I would use a single siphon 1" bulkhead with 1.5" drain pipe below and flip the second over as a safety siphon... That's how I run my current cube... I mean honestly that's how every tank I have ever owned ran the extra durso never had a purpose.... Hth any more questions lmk I would love to help...

 

[blurry]

Thanks for the Quick response!

Two questions-
(1) what is the benefit of running 1.5" drain below the 1" siphon drain stack? The resin I'm interested is the 1" has less water volume and that is of benefit handeling the back flow from the tank when the pump is off.

(2) what is the advantage of pointing up versus a durso pointing down?

Thanks again for the help!

 

[Troylee]

You want a 1.5" durso stack and 1.5" below or 1.25" for both.... Both would work either one will reduce only at the bulkhead and open back up to 1.25" or 1.5" I always use 1" bulkheads and 1.5" plumbing makes it really silent and handles 3500gph easily!!!! Also having the second as a emergency siphon it will allow it take all the flow in case the main gets clogged... When air is introduced into a durso it kills the flow drastically.... For instance a single 1" full siphon drain can handle 2300gph iirc......

 

[blurry]

Thanks for the responses! I wasn't clear about the returns - it is 1 1/2 up to the tank and then goes into two 3/4". The pump is a dolphin 3600 which pushes ridiculous amounts of water (and is just as power hungry!).

The float switches for emergency overflow (hopefully never used) would be run to a reefkeeper using the same logic i use on my system which is to shut the return pump down for X minutes before trying again. I have mine set for 5 minutes with a low sump level switch tied to the same circuit.

here is a quick sketch (note that this really should be in 3D, the returns go 90 degrees apart, one to the front, one to the side, you get the idea ):

THANKS!

 

[Troylee]

Yeah nothing wrong with that setup but I would run it as a full siphon and a emergency siphon not sure the standard durso can handle all that flow if the main got clogged.... Just my thoughts...

 

[Hahnmeister]

FWIW, Bean's design doesn't need 3 pipes for the overflow, 2 will work just the same (Herbie method). Unless you are running a very shallow overflow its actually pointless. All you need is the primary drain line that is controlled with a gate valve and then a secondary overflow set up like a durso that is used as a backup to the primary line. The reason Bean made his with 3 drains is because he uses smaller pipes with respect to the water flow. As long as the secondary overflow can handle the entire oveflow volume of water in the event of a clog in the primary line, the 3rd pipe is pointless. Ive been using the 2-pipe method for years. Its silent and just as failsafe.

Here's the evolution of my overflow:

The basic Herbie 2-pipe method; I add more noise control and strainers on the intakes: