Eshopps overflow box

[Charney]

I am looking at some of the Eshopps overflow boxes and want to know if there is a min flow rate for them to work. I am looking at the 1200 rated for 1000 gph and the 1800 gph that does 1600 gph. Is there a min flow rate that is is needed to keep the siphon. I am looking to use the overflow on 180 gallon and use a pump that runs 1000 gph. I know with the head loss it won't really be pushing this much water. Can I use the larger eshopps in case I want to increase the pump one day or do I have to worry about enough water to keep the siphon?

 

[shookONES]

You'll be alright in either case, but a closer fitting pump does a much better job at keeping air bubbles out of the U tubes.

 

[ShadowStryder]

I have two of the 1600 on my 340 and they dont get close to 1600 gph each. I have a mag 24 with about 6 ft of head and the mag runs wide open. Id be shocked if I get anything more the 1600 combined on the overflow boxes.
Go with the larger size would be my advise.....

 

[softturtle]

You can always get different u-tubes if trapped bubbles are a concern. That is where the problem would be if there is a problem. Really can't have an issue of not pushing a gravity fed bulkhead hard enough.

 

[ShadowStryder]

I know in my situation I have no bubbles and never do now. I put 3" stand pipes in mine which increased water level eliminating bubble issues.
I think the teeth limit how much flow. When I tried to run dual utubes the water coming through teeth could not keep up.
Dont get me wrong they are functional and I have never once lost syphon in 5 years in several power outages.
Honestly I think you could run it in a herbie style at full syphon and achieve much more flow but have never got around to trying it.

 

[Cu455]

There is a min flow rate, I am not sure what it is. My pump was not pumping enough water to hold a syphon on a eshopps with 2 u tubes. I removed one and everything was ok after that. You can also use u tubes with a smaller diameter if it is an issue.

 

[Charney]

thanks for all the input. From what i read you should only get bubble accumulation if there is not enough flow. I am aiming for a 1000pgh pump so I will try the bigger one.

Is it made to add U tubes or is i more of a DIY thing? Can you buy larger diameter?

ShadowStryder if you went herbie style wouldn't you loose your siphon in a power outage?

These will be going on a 6 ft and 8 ft tank. Would I be better with one bigger overflow box or two smaller ones? Which would be better for circulation? thank you

 

[ShadowStryder]

I would run two larger. Oversize your pump just a little and you can put a valve on your return line and throttle it down a little if need be. Or you can also T it off back to sump with a valve to control if your pump is to strong. ( or even to a reactor)

The large eshopps has 2 drains so you could use one at full or partial syphon and one for emergency drain but it would be hard since they arent very deep. You would have to remove teeth and tinker around with it to see how it would work. Which is why I never got around to doing it

 

[ShadowStryder]

To better understand your question, you wont lose syphon because they have a compartment in the middle of the outside container with walls that hold enough water to keep the utube submerged. So no it doesnt lose syphon. Even if you dont use stand pipes in the bulkheads it doesng lose syphon.

 

[Charney]

thank you for the info. I will try to contact eshopps and find out the min flow for each box