Thinking about overflows...

Still planning out a 90g reef tank...I was wondering if anyone sees a problem with my logic on this....

-I want to avoid hang on back overflow boxes.
-I like the idea (surface skimming ability) of a california/c2c style overflow, but I feel like it'd be crowding my aquascaping hanging over the top with only 18inches of depth in the tank from front to back. So I thought about getting or making two of these...

Austin Oceans - Overflows

My thought was to drill and install a bulk head into the back of the tank with a small overflow box in one corner. Then do the same thing in the other corner but with two bulk heads. The single bulkhead would flow to the skimmer side of the sump, as would one of the two bulkheads in the other corner. The last bulkhead would flow into the refugium side of the sump and regulated by a gate valve. Each bulkhead would be attached to an external standpipe (durso or other).

Anyone see a problem with that? Had any experience with something similar?
I'm trying to give myself options for flow regulation to the sump/fuge and not have to worry about flooding due to lost siphon, etc... Also I thought it'd save me some real estate as opposed to corner or center overflows that go from tank floor to rim.

Thanks folks!

 

I would just drill one hole for each of the overflows in each corner. 2 holes total. Then just tee off one of the drains with a gate valve to control flow into your fuge and then off other the other side of the tee just run your pvc to the skimmer portion of the sump. I don't really see the need to have a dedicated bulkhead drilled just for feeding your fuge, It's pretty low flow down there anyway and there's easier ways to get water through.

 

Those look like nice overflow boxes and I agree 100% about not using HOB/siphon overflow boxes. I could never sleep at night with one of those things on my tank.
I think your basic concept is sound about the overflow boxes etc. I would look into the Herbie and BeanAnimal overflow/drain designs though (I'm sure you can google for them). They will give you redundancy and a completely silent drain system.

If you're planning on having 3 bulkheads already the BeanAnimal design would be almost a no-brainer IMO, you could have your main drain go to the skimmer, have the secondary go to the refugium and have the emergency go to the skimmer or the refugium. Or you could maybe tee off the main drain under the tank and send some to the refugium and some to the skimmer and have the secondary go to the refugium as well.

 

I drilled my tank for overflows and all I did was drill 2 holes for seperate overflows(1 on each back corner of the tank) made my own overflows for about $12 you can pick up the needed items at any hardware store, and ran 1 to the skimmer side of my sump and the other to the refugium side of the sump and then stuck my return pump in the middle and drilled 3 holes for my returns. I could post some pics if you want.

 

Pics would be great. Thanks!

 

I guess I was thinking that by having a second dedicated hole for the main part of sump would be that it leaves a little bit of redundancy to the system. It also gives me options to use different kinds of standpipe systems (like the bean animal, which I think needs three standpipes?) That way I was pulling surface water to the skimmer from two ends for better removal of DOCs and increased gas exchange. Maybe I'm overkilling it though. Definitely something for me to think about. Thanks!

 

Here is how I made my overflows. They also work really well. They are small and out of the way. On the back side where it goes down to the sump I also have air valves so I can control the amount of surface skimming by opening or closing the valve.

 

Very nice. Then what'd you do from the overflow down? Just a bulkhead and some pvc?

 

Yes just use a bulkhead inside the overflow and then some pvc or clear flex hose from a pvc elbow after the bulhead. In the top of the elbow is where I drilled two holes and installed the air valves. I found if you dont do that it can gurgle pretty loud. The air valves fixed that though