Bulkhead Question

Shewillbemine · 12/11/2008, 06:42 PM

Hi there,

I'm venturing into a larger aquarium and the model I'm looking at has three holes drilled in a perfect line near the top on the back wall. The outer two holes on the left and side are for return lines and the middle, largest one is for the overflow down into the sump.

(I've never used sumps or overflows before)

QUESTION: What is the design/tool/equipment used for the drain in the middle, large hole? Is it simply plugged in by a plastic bulkhead and the water leaks through down a pipe into the sump? To me, that seems like the water level is cheated by 1-2 inches and would take away from a "clean, flush look" for the water level and tank top edge.

Or do I install an internal overflow box that will skim the water, leak into the box and through the hole (with bulkhead fitting of course)?

Please help a noob. Thank you!

der_wille_zur_macht · 12/11/2008, 07:00 PM

Can you draw (or take) a picture to show these holes?

If they are truly in the back pane of glass a few inches from the top of the tank, they're probably not ideal for returns OR sump drains, without some supporting equipment. Putting a drain that far below the tank's top would indeed mean that you would lose some volume. And, putting returns below water level is NEVER a good idea, since back-siphoning will drain your tank to that point any time the power goes out or you turn your return pump off.

One approach would be to use glass or acrylic to build an overflow box around the three holes. That way, you could use them as you described, though the two "return" holes would have to be plumbed out of the box. So, you might want to use those two for a closed loop instead, and just plumb the returns over the back wall of the tank.

Typical construction for the drain to the sump is to have an overflow box around a bulkhead. In most factory built tanks, this bulkhead is in the bottom of the tank, but a wall-located bulkhead is fine, too - it just changes the way you'd plumb your drain line and standpipe.

Search the following terms on here to get some ideas:
overflow
standpipe
durso
stockman
return

Also, check out melevsreef.com and poke around, he's got a lot of good sump and overflow info.

Shewillbemine · 12/11/2008, 07:07 PM

Thank you. Here are pics of the tank I'm looking at. Please note the three drilled holes in the back, top wall. The water line also leads me to believe that the water simply siphoned through a bulkhole fitting (now removed) into the piping.

der_wille_zur_macht · 12/11/2008, 07:08 PM

It's really hard to see in that pic, but it looks like you'd definitely need an overflow box around the middle (drain) hole.

How many gallons is that thing?

Shewillbemine · 12/11/2008, 07:14 PM

60. It's a 24 cube (and if you click the pics, they get bigger).

12/11/2008, 06:42 PM	#1
Shewillbemine Registered Member Join Date: Oct 2007 Posts: 195	Bulkhead Question Hi there, I'm venturing into a larger aquarium and the model I'm looking at has three holes drilled in a perfect line near the top on the back wall. The outer two holes on the left and side are for return lines and the middle, largest one is for the overflow down into the sump. (I've never used sumps or overflows before) QUESTION: What is the design/tool/equipment used for the drain in the middle, large hole? Is it simply plugged in by a plastic bulkhead and the water leaks through down a pipe into the sump? To me, that seems like the water level is cheated by 1-2 inches and would take away from a "clean, flush look" for the water level and tank top edge. Or do I install an internal overflow box that will skim the water, leak into the box and through the hole (with bulkhead fitting of course)? Please help a noob. Thank you!

12/11/2008, 07:00 PM	#2
der_wille_zur_macht Team RC Member Join Date: Sep 2003 Location: NY Posts: 17,749	Can you draw (or take) a picture to show these holes? If they are truly in the back pane of glass a few inches from the top of the tank, they're probably not ideal for returns OR sump drains, without some supporting equipment. Putting a drain that far below the tank's top would indeed mean that you would lose some volume. And, putting returns below water level is NEVER a good idea, since back-siphoning will drain your tank to that point any time the power goes out or you turn your return pump off. One approach would be to use glass or acrylic to build an overflow box around the three holes. That way, you could use them as you described, though the two "return" holes would have to be plumbed out of the box. So, you might want to use those two for a closed loop instead, and just plumb the returns over the back wall of the tank. Typical construction for the drain to the sump is to have an overflow box around a bulkhead. In most factory built tanks, this bulkhead is in the bottom of the tank, but a wall-located bulkhead is fine, too - it just changes the way you'd plumb your drain line and standpipe. Search the following terms on here to get some ideas: overflow standpipe durso stockman return Also, check out melevsreef.com and poke around, he's got a lot of good sump and overflow info. __________________ Inconveniencing marine life since 1992 "It is my personal belief that reef aquaria should be thriving communities of biodiversity, representative of their wild counterparts, and not merely collections of pretty specimens growing on tidy clean rock shelves covered in purple coralline algae." (Eric Borneman)

12/11/2008, 07:08 PM	#4
der_wille_zur_macht Team RC Member Join Date: Sep 2003 Location: NY Posts: 17,749	It's really hard to see in that pic, but it looks like you'd definitely need an overflow box around the middle (drain) hole. How many gallons is that thing? __________________ Inconveniencing marine life since 1992 "It is my personal belief that reef aquaria should be thriving communities of biodiversity, representative of their wild counterparts, and not merely collections of pretty specimens growing on tidy clean rock shelves covered in purple coralline algae." (Eric Borneman)

12/11/2008, 07:07 PM	#3
Shewillbemine Registered Member Join Date: Oct 2007 Posts: 195	Thank you. Here are pics of the tank I'm looking at. Please note the three drilled holes in the back, top wall. The water line also leads me to believe that the water simply siphoned through a bulkhole fitting (now removed) into the piping.

12/11/2008, 07:14 PM	#5
Shewillbemine Registered Member Join Date: Oct 2007 Posts: 195	60. It's a 24 cube (and if you click the pics, they get bigger).