External overflow through a bulkhead?

[Myka]

Anyone using a bulkhead to provide flow for an external overflow? I'm trying to figure out a way to do an external Herbie overflow on my nano, but want to avoid the bulk of an internal overflow box. I don't have the ability to grind a long U shape in the back pane of the tank for an overflow, so I'm looking at ways to get the water out with bulkheads. I'm only looking at about 150-200 gph through the overflow.

My first idea is a single 1" bulkhead through the tank with a basket strainer on it. This goes into an external overflow box with two standpipes for the Herbie. The basket on the bulkhead in the tank will be 1-2" below the water surface with the Herbie controlling the water level in the overflow box which when plumbed this way will match the water level in the tank itself. I'm not sure I like this idea.

My second idea is two 3/4" bulkheads through the tank with basket strainers. No overflow box at all. These would be plumbed with a gate valve on one to control water level as per Herbie, and the other would be the emergency drain. This would require 90 degree elbows in the tank otherwise the water level would end up being too low since I can only drill so close to the top of the glass. I'm not too keen on having gaudy white elbows in the tank, but this seems like a much safer idea.

My third idea is to find out how much the glass company would scam me for to grind out a U-shaped section for a perdy "pro" external overflow. Hmm...sounds expensive, and risky for the tank.

Anyone have a better idea?

[Dez]

You know that the u-shape notch at the back of the tank is the best idea without any visible plumbing in the tank. Maybe go buy a dremel and do it yourself?

[Myka]

I have a Dremel...that would probably take several hours. I have tried using the Dremel to make similar cuts and made so little progress in 30 minutes that the project was abandoned. I don't have that patience, I would break the tank due to lack of patience.

[lockrookie]

myka go to my 50g thread i did this and the bit i used worked excellent its not that hard. if you where in regina and it was warmer out id do it. dont have a heated garage also i used a larger router than a dremel for higher rpm.. wear safety glasses

[Myka]

I checked out your thread, and that worked out pretty good for you! You do comment on braking glass from a 10 gallon tank though, so I worry about this nano...the glass is not very thick. I should measure it, but I think it is just 4 mm.

[jostafew]

Hey Myka, are you building from scratch or are you modifying an existing tank? I'm doing exactly this on my upcoming nano build (external herbie) but I'm going the be building the u-shaped back panel from one large panel and two smaller ones. Will be cheaper to snap a couple smaller pieces than to try to get that shape cut into one panel and since the back wall will painted the seam won't really be noticeable anyway.

Here's my tank concept:
http://www.reefcentral.com/forums/sh....php?t=2096996

[lockrookie]

Originally Posted by Myka

I checked out your thread, and that worked out pretty good for you! You do comment on braking glass from a 10 gallon tank though, so I worry about this nano...the glass is not very thick. I should measure it, but I think it is just 4 mm.

i only broke the glass cause i was stupid and didnt pay attention not by cutting it. i had forgot a pipe was attached and moved it... then i tried to lift the tank by the overflow...not my brightest moments but lesson learned.