Looking for internal overflow advice (1 Viewer)

[Guest]

I have a Oceanic 135 gallon show tank that I would like to make reef ready. It is 72 1/2"L x 18 1/2"Dx 24 1/2"H. I am planning on making two 3-sided internal overflows out of black acrylic and would like to put bulkheads on each side of each overflow ( 2 per overflow ). One of the overflows will go to a closed loop that will contain inline carbon and heater modules, the flow rate should be around 800 GPH for this loop. The other will go to a sump/refugium with skimmer and the redundant heater.. undecided flow rate at this time. I would like both returns to split via a SQWD (1400 GPH max) before entering the tank. These split returns I would like to come out of the overflow bulkheads. So, each bulkhead will have 1 drain and 2 smaller returns. Does that make sense? So my questions are as follows:

1. Is this a good design? ( this question assumes that my description makes sense...)

2. How big should the holes/bulkheads be?

3. Given these 3 bulkheads at the bottom of each overflow, how big should the overflow be? (Is there a recommended space between the edge of the tank and also between other holes?)

I would appreciate any feedback on this

 

[Guest]

OK, don't everybody speak up at once!

I found a pretty cool Discharge Rate Calculator online:

http://www.grow.arizona.edu/water/rateofflow/flowoutanopening.shtml

Basically, at a depth of 20", the discharge rate of a 1" hole is about 1500 GPM. Since I want SQWDs on the return I can only push it to a MAX of 1400 GPM. Since a 1" hole is enough, I will install 1" bulkheads for the drain.

The SQWDs have 3/4" outlets so this is my narrowing factor on the returns. I will 2 install 3/4" return bulkheads beside each 1" drain bulkhead.

Each internal overflow box must be large enough to contain the drain stand pipe and the 2 returns that have to bend to go out the side bulkheads that are going to be on the box itself. I also don't want them to take up too much space in the tank. I figure I can get all of this in a box that comes out 6 1/2" from the back and is 9" wide.

 

[Guest]

OK, I found the drain calculator on the RC site. It recommends a 1.5 inch drain for a max of 1400 GPH. I don't really want to go this high, this is just my max guideline. It also recommend 21" of linear space on the overflows and my current idea supports that.

The problem with my design is that I have 1 overflow to a sump which is fine. The other goes to a closed loop, which does not make sense, don't need an overflow for that. Maybe I'll stick with the 1" drains and have both going to the sump, and then drill another hole for the closed loop drain. The return from the sump will come thru one overflow box, and the returns from the closed loop will come thru the other.

I know you're thinking that I'd be better off with 1 larger overflow in the center, but the center brace is in the way and I don't want to mess with that. Plus the 2 boxes will offer much more surface skimming.

You know you're goin' crazy when you start talking to yourself

 

[Guest]

WIsh I could help you out, but you just spoke a whole lotta german to me.

I'm in near the same boat, oceanic 110 long, 72x18x24, and have been considering putting in one or two overflows, but don't know how many I really need...*sigh*...

Guess I'll get it figured out next weekend...

 

[Guest]

I'm in near the same boat, oceanic 110 long, 72x18x24

These are the dimensions for an Oceanic 135 gallon Show. The 110 Show is a foot shorter.

As far as waiting a week.. I've been waiting months! I am finally putting some real thought into it though as it's been sitting in the garage long enough

 

[dobber99]

Drain

I have a 75 acrylic with two 1" drains going to my sump/fuge. My return is a Mag 12 going to a scwd (the scwd works great swithces about every 6-7 seconds). The water level rises to about 1/4" from the top of the drain holes, and when I place the snail guards over the drains, the water level rises almost to the top of the drains. There are three bends total per drain going to the sump, and using 1" all the way. I finally figured out how to post pics, so If you want I can show you my diy nozzle returns with adjustable tips (for flow), and the water level in the aquarium. Hope this helps.