Dual corner internal overflow plumbing

[gunit]

I‘m designing my tank build as we speak and have started to consider doing dual corner overflows instead of a center overflow. Trouble is I only have two drain pipes (plumbed down to my garage). Would it be crazy to join the full siphon and emergency drain pipes from each overflow together so that each overflow combines into a central main drain pipe and emergency drain pipe?

Something like:

As you can likely tell from the diagram I plan on running a full siphon on the 1 1/4” main drain and have a 1” back up drain.

Is this a bad idea? I think tuning the full siphon would still be doable and don’t think I’d be risking flooding since with a full siphon I should be able to still drain 1000gph+ (I think). Plus I’d still have the 1” emergency which still should be able to handle close to 1000gph. Looking at between 600-800gph on my returns.

 

[Doctorgori]

Just clarity: you Actually “want” dual overflows?
I dunno, I have 2 internal dual overflows and absolutely hate it... emphasis on hate!
my opinion: but regardless of 2 drain pipes, for the love of Pete, reconsider...

 

[Lasse]

For the siphon part - I would consider to have a gate valve on each siphon drain but it will probably work the way you suggest too - you get corresponding vessel and the level in both overflow chambers will be the same. This means that it will work for the emergency drain pipe too but you need to be very careful into get exactly the same height in the separate overflow chambers - IMO

Sincerely Lasse

 

[gunit]

Thanks. Yeah putting a gate on each full siphon branch makes sense. That'll help with any slight differences in heights of the drain pipes correct?

 

[gunit]

Just clarity: you Actually “want” dual overflows?
I dunno, I have 2 internal dual overflows and absolutely hate it... emphasis on hate!
my opinion: but regardless of 2 drain pipes, for the love of Pete, reconsider...

Yeah I keep going back and forth what would bug me less. I was just trying to minimize the visual impact of the overflows and also try to not impact flow patterns too much.

What about the dual corners do you hate?

And before anyone suggests, based on the setup of the room, an external overflow isn't an option

 

[Doctorgori]

Yeah I keep going back and forth what would bug me less. I was just trying to minimize the visual impact of the overflows and also try to not impact flow patterns too much.

What about the dual corners do you hate?

And before anyone suggests, based on the setup of the room, an external overflow isn't an option

its the doggone dead spots and the acreage .. .. Aquascaping around the overflows is a pain ... if I had a do -over I’d go with a internal coast to coast or perhaps almost coast to coast ...