Set up help

[HockeyRooster]

I bought a 90 gallon tank with a two drain overflow and sump system. I don’t have the ability to drill any more holes.

I will say I’m a bit concerned about the single drain. Would it make sense to use both of these as drains with the small one being the emergency?
Then I would plumb the return up and over the edge of the tank. I’d be okay with that.
any other ideas or suggestions? Thanks

 

[Larry L]

If you're ok with plumbing the return up over the edge, then I'd definitely use the two existing holes for drains. It looks like the holes are different sizes, so I'd make the bigger hole the main full-siphon drain, with a below-water-level strainer on the top and a gate or ball valve inline on the way the the sump, and then use the smaller hole for an emergency drain with either a Durso or a Maggie Muffler on top at water level.

 

[HockeyRooster]

If you're ok with plumbing the return up over the edge, then I'd definitely use the two existing holes for drains. It looks like the holes are different sizes, so I'd make the bigger hole the main full-siphon drain, with a below-water-level strainer on the top and a gate or ball valve inline on the way the the sump, and then use the smaller hole for an emergency drain with either a Durso or a Maggie Muffler on top at water level.

Thank you!!

 

[R.Weller]

Great idea using both as drains. It will be virtually silent & when it isn't, that's an indication that maintenance is required (cleaning the strainer). Generally speaking, the larger pipe is the emergency as it is expected to handle the full load from the return pump(s). Have a look at this resource.

Herbie Overflow Plumbing Guide for Quiet Reef Aquariums - gmacreef

The Herbie method can quiet down your aquarium drain and eliminate microbubbles. The guide includes helpful diagrams and explains each component.

gmacreef.com

 

[Larry L]

Generally speaking, the larger pipe is the emergency as it is expected to handle the full load from the return pump(s).

That's a good point - probably better to do it that way than the other way around like I suggested.

 

[HockeyRooster]

Thanks guys. The drain sizes are 3/4” and 2”. That 2 inch drain seems really big and I don’t know why.
Now that I’ve given you the sizes do you still think I should use the small as the main drain (siphon drain with valve)?

 

[R.Weller]

Yes. I would still use the smaller as the primary drain & the larger as the backup / emergency.

Here's a quick illustration:

There is a huge difference between in the flow rate of 3/4" & 2" (approx 5x), even if you block the 2" with a gate valve. It's not so much that the 2" pipe would clog, but the fact that you would already be reducing the pipe using a gate valve, & when the strainer clogs (& it will from algae & other creatures / particles) the 3/4" drain will be used. If your 2" is the primary, you would need to restrict the 2" to the size of the 3/4" regardless. Better to allow the 2" to be fully reserved as the emergency & be absolutely confident that it will never fail. You could even allow the 3/4" to 'be dirty' for a little & stay clogged given the size of the emergency.

 

[HockeyRooster]

Thank you!! This forum is amazing and I really appreciate the chart.

Just hit Home Depot for some more fittings. After feeling overwhelmed by the project initially I’m starting to feel good about this new set up!