quick question on overflow holes?

[geaux xman]

so i should be getting a custom 150gal tank. i've never had a tank with an overflow.

are 2 drilled holes okay? if so, what size? need to know, so i can tell the builder. the quotes he is giving me is with 2 holes.

i see some setup's with 3 drilled holes. 1 1.5" drain and 2 3/4" returns?

i've also seen some mention a safety drain? not sure what that means.

[Sisterlimonpot]

Oh man the possibilities are endless. I would definitely go with more than 2 holes. With a 150 you'll want at least 4 (2 return and 2 drains) or you can go with the beananimal design (google it) and then you have to decide if you want a closed loop system or if your going to use power heads. like I said... the possibilities are endless

[geaux xman]

nah, i'm not doing beananimal. its a 60x30x20 rimless, so it will likely be a center overflow box.

so would 1 1.5" drain and 2 3/4" return be okay?

this is my first time really reading up on the details on an overflow. doing a search right now.

[aleonn]

As a minimum, one 1.5" drain and two 3/4" returns are okay. But for redundancy and more flow, two 1.5" drains and two 3/4" returns are better. You can always use circulation pumps in the display tank to increase flow as well.

[trb]

I would never have less than two drains, a main one and an emergency. What happens if one of them clogs up or something? A big wet mess on your floor.

Good luck!

[chimmike]

Not only that, but 1 durso isn't going to drain the turnover you want, and one siphon without an emergency is a bad idea.

If you can fit the beananimal, do it. Or drill and make an external overflow box like I did.

[RocketSurgeon]

http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx

Can't go wrong with this!

[RiddlerJoe]

I'm assuming he ruled the beananimal design out as he wants to use the tank in the center of a room. He did say he wanted a center overflow.

My suggestion would be figure out your pump flow, then match or exceed that in the drains. Just remember if your using a 1.5" pipe the bulkhead hole is going to be larger. Before you drill you should aquire your bulkheads and plumbing and plan it out.

Here's a quick chart of flow rates for the different size pvc pipes.

Conservative estimates for bulkhead flow rates are as follows:

•3/4 inch - 350 gallons per hour per bulkhead (unconfirmed).
•1 inch - 600 Gallons per hour per bulkhead.
•1.5 inch - 1,500 Gallons per hour per bulkhead.

How large of a center overflow box are you planning? The larger it is, the easier to fit your hands into, to get the bulkheads and plumbing right. Too larger and you lose your display area. You also need to plan out wether or not the returns will be located withing the center overflow box. If so you'll need more room.

My opinion is to use 2 drains in the box with 1 return. Then split the return, so only one bulkhead but it's split after the bulkhead for to retun ports.

Riddler

[geaux xman]

Thanks for the responses.

i'm not doing the drilling myself, miracles will do it. i'm just trying to decide how many drilled holes, so i can get all my ideas down before i contact and start the build. so i'm not sure how big the center overflow box is yet but i'm sure they have all kinds of sizes.

I'll probably just do as Riddler and others have suggested:

1) 2-1.5" drains(1 safety), and 1-1" return
eheim 1262 (900gph-overhead loss)

Then I will add Koralia Magnum 6(2200gph). This will be FOWLR, so I dont need a ton of flow. Later a MP40.

Seeing this CL setup, did give me all sorts of crazy ideas, but probably way more complex, and expensive than i want.
This is 72x30x24. my tank dimensions will be similar to this, but 60x30x20.
http://reefcentral.com/forums/showthread.php?t=1535215

2 island overflows with 2 (2")durso style drains
2 (1") external (outside overflow to keep size down) returns
2 (2")intakes for CL's;
http://i49.photobucket.com/albums/f278/summerofmyyouth/IMG_1281.jpg

http://i49.photobucket.com/albums/f278/summerofmyyouth/IMG_1291.jpg

if anyone have some CL ideas, feel free.

[chimmike]

that'll be fun to keep clean, lemme tell ya!