Squidd - tank spec follow up

[trompet3]

Squidd or anyone -
I am finalizing my tank specs and have decided on a GC 60"x36"x25". I am having 1 overflow made in the center of the back wall.
My question is what dimension should I make the overflow to handle flow through one 2" bulkhead and one 1.5" bulkhead combined. I am really only using the 2" as a drain, and having the 1.5" set higher only to be used if the other gets clogged. But, I want to make sure that the overflow size can handle both in case I decide to use it later. (There will also be a 1" return bulkhead in the overflow, but isn't too relevent to this discussion besides space).
The only other thing to consider is that there will be eurobracing above the overflow and would like to have room to access the overflow and put in a 2" durso etc. I don't know how wide GC usually makes their eurobracing though. Maybe someone does.
Thanks. I would have done these calcs myself, but don't know the formula.

 

[robchuck]

A 2" drain will comfortably allow about 2200gph to flow through it. The calculator I used to come up with that figure also recommended a linear overflow length of 33 inches to handle 2200gph. Figure that a 2" Durso standpipe is going to take up a lot of room, so an overflow box of 8" wide is probably reasonable. Because this is a center overflow, the 8" figure gets doubled (because the box has two sides) to 16". 33"-16"=17".
So a center overflow box with the dimensions of 17"L x 8"W should work well up to 2200gph.
The width of the Eurobracing on GC tanks depends on the size of the tank. FWIW, the Eurobracing on the GC tank I owned for awhile was 4" wide all the way around.

 

[trompet3]

RobChuck, thanks for the reply.
What dimensions would I need for flow through both the 2" and 1.5" combined?
How would I go about getting this calculator you are using?

 

[robchuck]

Search Google for: "overflow size calculator"

 

[squidd]

My question would be ....Where are you flowing 2200gph+...to...??
Your going to need a pretty decent sized sump to be able to handle that kind of flow without having bubble and noise issues...
Are you trying to get all your flow from the return pump, or will you be adding supplemental flow devices...?

 

[trompet3]

I'm not going to push 2200gph now. I just want to have the option later. I figure better to plan for it now and not worry later. I do want to make sure that the overflow will match the 2" and 1.5" combined rate now.
The main flow for the tank is going to be through an 8 way OceansMotions with a sequence Hammerhead. I'm attaching the current plans for the back and overflow. The 1.5" holes are for the hammerhead intakes. There are 2 holes missing from the pic. Those will hopefully be drilled into the eurobracing near the back corners.
What do you guys think? I just need to get the overflow and eurobracing dimensions figured out so I can go ahead and place the order.
Thanks for the input!

 

[acrylic51]

Like Rob said the plan for the overflow looks good.....The sizing of the eurobracing depends on if the tank is going to be cross braced or not. If you have Tom build the tank without cross bracing you will have wider eurobracing than normally to compensate for the cross bracing......I opted not to have cross bracing, but adjusted the width of my overflow to allow easy access inside the overflow box...
That's alot of holes in the back wall....I think you'd get more out of the 4 way than the 8 way. The flow pattern or sequence is better IMO on the 4 way than the 8 way. I was opting for the 8 way, but after talking to Paul in some depth he showed me the advantages of using the 4 way instead... Have you called and spoken with Paul?

 

[trompet3]

I did speak with Paul. He recommended going with the v.3 of the 8-way. The drum is best balanced in this setup as it is activating flow through opposite sides at the same time. I do not think that the 4 way would give me the flow I would like. I want to have a good portion of the 8 returns blowing only into the crevices/live rock/bottom. So if I only had 4, then that doesn't leave many returns for flow in a 240g tank imo.
I ordered the tank as is pictured and made the overflow 17" x 8". The eurobracing is 4" on the back and front and 6" on the sides in order to accomodate a 1" bulkhead on both sides of the bracing for the other two returns. Those need to be at least 2.5" away from the wall in order to allow for clearance for an OM Revolution if I choose to have those at some point. I am having him drill for sched. 80 bulkheads.
Now I need to start building a stand! I'm a beginner in carpentry so I'll be starting a new thread for that!

 

[acrylic51]

Cool beans!!!!!!! Congrats on the new tank.... Why couldn't you split the lines off the 4 way to get more outlets instead of 4?

 

[trompet3]

I could have, but then I'd cut the flow through each return by about 1/2. Plus, the difference in price between an 8 way and 4 way is not much.