Overflow placement - 1 vs 2 returns?

[Easto]

I have unleashed my windows paint skills on this one!

I have a 48" tank
Lighting is 2 Kessil LED

I am going to drill a Bean Animal Overflow.

My overflow box is 4" (deep) x 10" (high) x 12" (long)

The 12" side has slots in it for water flow. The 4" pieces on the side are solid acrylic - no water passes through the sides.

These are the three setups I am contemplating.

1. Overflow in the corner with 1 return line at the far end.

2. Overflow in the middle with 1 return at the end

3. Overflow in the middle with 1 return on the left side and 1 return on the right side.

From my understand all of these should be fine as long as circulation WITHIN the tank is good.

I planned to go with option 1, but if there is a good reason to do something different I'm all ears.

[reefmandan]

I like option three the best. More returns is better for flow ... especially along the back wall (depending on how exactly you arrange the return flow). I also like three for the placement of the box. The whole idea behind the weir box is to maximize surface skimming, and by positioning the box in the middle, you give more access to surface waters across the whole area of your tank to be skimmed over the weir.

[The Guy]

Originally Posted by reefmandan

I like option three the best. More returns is better for flow ... especially along the back wall (depending on how exactly you arrange the return flow). I also like three for the placement of the box. The whole idea behind the weir box is to maximize surface skimming, and by positioning the box in the middle, you give more access to surface waters across the whole area of your tank to be skimmed over the weir.

Agree #3 is the best option, this is basically what I have in my RSM250 works very well with some directional nozzles on the returns. you may want to add some powerheads to help with lower tank and reef circulation.

[Easto]

For power heads I have an MP40

I'll probably add 1 or 2 Korillas once it's up and running and I see where I need the extra flow.

[Aquattro]

My return simply returns water from the sump. I only have (maybe) 400gph, so regardless of how many lines I use, it's not adding to flow in any amount worth worrying about. The only time I used dual returns was on a 150g running a MAG 18, and even then the flow was minimal.
IMO, use the return pipe how it best fits and address flow using pumps designed for that.

[e46er]

A centered overflow I feel would be SLIGHTLY more beneficial for surface skimming but that said an end overflow would be much less intrusive and allow for easier flow in the tank and less potential dead spots sooooooo at the end of the day I'd say they cancel out. Personally I'd go option one but this is just my thoughts.

[Myka]

I have similar views of the bean animal as Albert does. I'd use the center hole for the return. I prefer side overflows to center overflows, but as Brad suggested, sometimes your plans change and the side overflow would become viewable.

[Snappy]

I would go with it centered and make it external if possible.

[maron6977]

I have a 4' 120g . Dual overflows , not in corner & I hate it !
My choice would be corner overflow , run the overflow at 45 degree angle .
Just my $.02

[byee]

Option 3 is the best.