Overflow advice Durso/Herbie

[Mark_C]

So I have 2 downpipes, 1", in the new tank. Never had 2 before, trying to figure out what to do.
I'm confused on flow, so I ask for advice.

The return from sump to tank will be split between 1 or 2 pumps and will be supplying 2x 3/4" returns as well as 2x 1/2" seaswirls, so I'm going to have at least 1200gph going back into tank (10x turnover).

I need to ensure I can get at least 1200gph down to the sump.
I understand that a 1" pipe will drain (via gravity) 600-800gph.
I know that a sealed siphon (eg Herbie) will pull more.

My return compartment is approx 2 foot high, with the weirs reducing the working water height to 18".

So, questions (I'm not going to do a bean)....

1) If I do a standard Herbie with 1" pipe, with the main siphon line 6-8" below the water line and a 2' drop into the sump, will it have enough siphon to pull down over 1200gph?

2) If I set up a Herbie then transform the emergency tube into a Durso it could function as both overflow and emergency drain (I doubt both drains would be blocked at once, especially with covers). I could set the level that allows increasing flow down the Durso if required. Would this be a more viable option?

Any thoughts or advice appreciated.

 

[Mrx7899x]

I would do a Herbie it can handle 1200 gph. 1200 gph is a lot of flow. I probably only have 800 to 900 gph on my 225.

 

[Mark_C]

If the Herbie will handle the 1200 that great, I'll go that way.

Per 1200gph, the problem is I'm running seaswirls that are powered from the sump return.
I may add a manifold to decrease flow through the 3/4" returns and increase flow through the swirls, then I think I'd be able to dial back enough on the return.

Wa initially thinking this...

 

[Mark_C]

OR, what about stealing the water for the swirls back before it gets to skimmer?

Something like...



Still would appreciate thoughts on Durso/HErbie combo or just Herbie, as well as thoughts on above 2 plumbing options for flow.

 

[Sponge]

Herbie no question. It’s better to have more siphon flow that you can dial back. gives you near limitless options for return

 

[Trio91]

If the Herbie will handle the 1200 that great, I'll go that way.

Per 1200gph, the problem is I'm running seaswirls that are powered from the sump return.
I may add a manifold to decrease flow through the 3/4" returns and increase flow through the swirls, then I think I'd be able to dial back enough on the return.

Wa initially thinking this...

View attachment 23124

Instead of a manifold, just maybe add a gate valve? But i guess that'll help for add ons down the line

 

[krusieski]

the more i read the more im seeing 10x is a thing of the past i would think you would need about 800gph


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[horseplay]

If you get a pump that's rated for 1000 gph you will probably get about 600 gph actual. I had about 400 gph as measured by the bucket method and it was enough for the tank.

 

[Mark Shelly]

I have 2 drains and did a modified Herbie. Definitely put a gate valve under the main syphon drain: it is hard enough to control with a gait valve, let alone a ball valve. I personally would not divert water anywhere from the syphon drain, especially before the valve as you don't want anything to act as an alternate route that will constantly change pressure. But I have no experience to say it won't work. I do believe it will make the syphon harder to control.

Do not valve off the emergency drain. Add a union if you like. When you turn off power, you will drain down to the syphon drain and the emergency will be dry.

Your flow should not exceed you emergency drain capacity (my opinion) as your tank could overflow before the secondary drain kicks into syphon mode. Make sure the durso has a top air hole. I put an elbow over the top or my emergency to quiet it down and it almost overflowed my tank when I dumped in 10 gallons of new salt water during a water change as air was not allowed to exit the emergency quickly enough.

 

[Mark_C]

I personally would not divert water anywhere from the syphon drain, especially before the valve as you don't want anything to act as an alternate route

Thanks for that. Wasn't thinking when i built the manifold. Restarting

 

[Mark_C]

We are now here...

 

[Mark Shelly]

If you wanted to or could, you could possibly pump to the swirls from the overflow and avoid the extra flow going down and the loss of pressure from lifting the water back up. And if so, you could even use a pulsing pump as it then wouldn't effect the flow down. I also don't see the advantage of a return before the skimmer unless there was no room after. After the skimmer section has the advantage of oxygenated water.

 

[Mark_C]

I thought about the return to the swirls from the overflow, but the limited real estate inside the overflow limits options to smaller pumps, which defeats the purpose of the swirls.

My thought of the return before the skimmer is to restrict the flow through the skimmer. Initially I figured I could kick back 500-600gph before water hits the skimmer, technically slowing down skimmer contact time. In my idiocy I didn't think to realize that the placement of the pump has no matter. It may as well be butted up next to the skimmer, and you're right, the oxygenatted water would be a benefit.

Damn, now I'm in to figuring out a way to return flow from the overflow, which would help negate another concern, siphon from the seaswirls in power failure. If they're pumped from the sump and the units are hard encased, there's no way to drill a siphon break at the waterline. In the overflow I wouldn't have to worry.