Silent and Failsafe Overflow System

[sean04]

Does anyone use a SCWD on the returns with this design? I'm thinking about using one but, I'm not sure if the fluctuations will disrupt the siphon or the silent part of this design.

Basically, my return will be split to two corners of the tank. My overflow is going to be an internal wier with an external overflow box. My tank is a 55 gallon with a 40 gallon sump.

 

[BeanAnimal]

Use an oceans motions... SCWDS are flow robbing junk

 

[Jgoal55]

Bean....any thoughts on my pics??

 

[BeanAnimal]

The pics look fine from what I can see. Do you see ANY bubbles being ejected from the siphon standpipe's outflow? How much higher did you raise the open channel weir compared to the siphon wier?

 

[Jgoal55]

Yes, there are definitely bubbles coming out of the siphon standpipe outflow. They "shoot" out every few seconds and it makes a semi-loud popping/ blurping noise each time.

The open channel weir is about a half inch higher than the siphon. Im not sure why there is air getting into that siphon standpipe????

 

[BeanAnimal]

You either have an air leak at one of the fittings or there are bubbles being sucked into the intake. In either case, they likely accumulate in the upper section of the standpipe until they pocket becomes large enough to get partially sucked into the stream. This is making the standpipes flow unpredictable and therefore it is going to be hard to keep adjusted.

 

[chasekwe]

Hey Bean, any reason your design wouldn't work with Flex PVC? I dunno if it'll ruin the siphon of perhaps interfere with the quiet function of the open flow?

Also, I thought the siphon and openflow standpipes were s'pose to be equal height?

 

[BeanAnimal]

Flex PVC is fine.

The siphon and open channel standpipes can be the same height. Moving the open channel a bit higher helps to ensure that that siphon starts. If the design is followed, there are no problems. Some people have not followed the design and have trouble with the siphon starting. Moving the open channel up just adds some extra ensurance that the is predictable.

 

[chasekwe]

Thanks Bean, ended up going with rigid PVC as the flex stuff I was looking at was gonna cost about 4x more. I'll probably stagger the standpipes I suppose, my setup is 3/4" with a bushing to 1 1/4" below the bulkhead... but I'm only gonna run around 300 GPH through it so I'll take all the extra help I can in getting the siphon going. Bought all my plumbing today in any event so here is hoping it'll work.

Btw, Home Depot has their version of the John Guest stuff... but there wasn't anything that was female threaded for me to hook the 1/4"Hosex3/8"Thread to. Anyone have any links to where I can buy the parts?

 

[sean04]

1) I would not waste the time with 3/4" pipe. Do 1" siphon and emergency, and 1.25" open channel.

2) 1" elbow of any type will work just fine. You make the box high enough so the water level is about at the horizontal center line of the elbows. With the inlet around an 1" or maybe a little less up off the floor of the external box.

3) "Length" of the overflow: Just about the entire length of the tank. (The long dimension) "Width" of the overflow describes the front to back dimension. "Height" describes the top to bottom dimension. If we all get on the same page, it helps keep things in order. "Depth" is ambiguous.

Tanks are described by Length x Width x Height.


Regards,

Jim

Just going back and thinking about this....do I need to do a 1.25" open channel for a 55 gallon w/40 gallon sump? What would be the maximum amount gph I can get with using a 1" siphon and a 1" open channel?

My pump is around 550-600gph after head loss.

Thanks.

 

[sean04]

Use an oceans motions... SCWDS are flow robbing junk

Thanks BeanAnimal. I will scratch this. What do you think about eductors? Sorry to go off the topic a bit. :fun4:

 

[TheCoralReef731]

Hi Bean. Thanks for this amazing thread!

I was wondering if its possible to have the three return lines drain into a larger return line, which then goes to the sump. Will this affect the siphon? I imagine it will make the siphon less powerful since it will shorten the amount of pipe involved. Apologies in advance if this has been asked before.

 

[snaza]

Hi Bean,

Great thread. I was wondering what size overflows you recommend for my 200g tank? Will probably have about 1500gph from the return. was thinking maybe 1 1/4 or you think 1 1/2 would be better? how much flow would a single syphon with these sizes handle?

thanks

Aaron

 

[mrvicz]

hello bean,

ive been following the thread, well most parts of it and im very convinced and thankful with your design. problem is I couldnt source a sanitary tee here in the Philippines. do you think it would be ok to use an ordinary tee instead?

big thanks in advance!

Vic

 

[MeuserReef]

I can help with these Bean....

Just going back and thinking about this....do I need to do a 1.25" open channel for a 55 gallon w/40 gallon sump? What would be the maximum amount gph I can get with using a 1" siphon and a 1" open channel?

My pump is around 550-600gph after head loss.

Thanks.

I run Bean's overflow on my 120 gallon and have all 1" plumbing. My return pump is a MAG 12 and I would say that I still have the ball valve on the sipon pipe 1/2 closed!

1" will certainly work for your flow rate. Heck, the open channel alone can probably handle 600gph!

do you think it would be ok to use an ordinary tee instead?

I use regular Tee fittings on my setup and they work just fine

 

[BeanAnimal]

Thanks...

 

[snaza]

How about me. Please:lolspin:

 

[reefermad619]

I run Bean's overflow on my 120 gallon and have all 1" plumbing.

Are you running an internal or external overflow? If internal, are you running the 1.25":1" street ells, or just 1" all the way around steets? I found some regulat 1" streets at Lowes for like $0.60 and I just want to make sure they'll work. Thanks.

 

[BeanAnimal]

Hi Bean,

Great thread. I was wondering what size overflows you recommend for my 200g tank? Will probably have about 1500gph from the return. was thinking maybe 1 1/4 or you think 1 1/2 would be better? how much flow would a single syphon with these sizes handle?

thanks

Aaron

Either will work. There too many variables to say how much either siphon can handle, but 1500 GPH is certainly nowhere near the maximum for any reasonably constructed siphon standpipe larger than 1" I.D.

 

[BeanAnimal]

Here is a rough estimate of "ideal" flow rates based in minimum I.D. of the standpipe.

In other words, ignore the word "bulkhead" and substitute the I.D. (the I.D. of hte bulkheads is listed to the right of the schedule designation) of the smallest fitting or pipe in the standpipe. The head is the distance between the surface of the intake pool and the discharge pool (or the exit of the standpipe if it discharges above the pool).

In other words if the distance between the ovwerflow's water level and the sumps water level is 12 inches and the smallest fitting has an I.D. of 1.5" then a rough estimate of the maximum flow of the standpipe under full siphone would be somewhere btween 2500 and 2900 GPH.

I only extrapolated the chart out to 12" becuase I made it for a different thread (talking about bulkheads in the side of a tank).

In the real world we have a lot of things that are not considered in the chart (friction, turbulance, air entrainment, viscosity, etc). So take the numbers as they are, rough estimates of "best case" flow.