# Help with sizing an overflow and bulkheads.



## AdamsB (Oct 18, 2011)

So im planning on ordering equipment for my new build (tank still to be determined but guaranteed 60-80 gallons) and I need some advice on an overflow. I'm going to be drilling the tank myself because I want to go with a herbie style. The problem Is I don't know how much water various pipe sizes drain. I had a google but couldn't find anything. Maybe I'm not specific enough. So anyhow, this is what I was hoping to use. 

Acrylic overflow box, 6 1/4" W x 4" D x 5" H made from 1/4 inch acrylic. So the inside dimension is 5 3/4 inches long. Ive looked at bulkheads and for a 1 inch hole I need 2.7inches. The herbie style needs 2 bulkheads so Its going to be tight, and I'm not sure I feel comfortable drilling holes so close together. This will be my first time drilling glass.

So I'm wondering if a 3/4 inch overflow will be enough to drain 800 gph. of course there will be 2 overflows but from what I read the emergency should stay dry unless theres a problem. I've already ordered my return pump. a Danner Mag 950 which Ive estimated to give me 800 gph return. 

My other option is to go with the next size up in overflows which is 12 inches long, that would give me ample room but look a little more unsightly. I could also look for a different overflow box but my main concern is what size bulkhead will i need.


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## The Guy (Nov 26, 2010)

I would go with 12" overflow box, I did exactly the same thing as you are planning. The herbie and E overflow are both 1" PVC, I also am using the Danner mag 950 pump which works very well for me and dump some flow back into the sump. here's a couple of pictures of what I did with my 90 G setup:
























I'm home today after 2pm for the rest of the day if you want call me with any questions. 604 856 4964 Cheers Laurie


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## AdamsB (Oct 18, 2011)

Thanks for the reply Laurie. After looking at your pic I think I'll up size to the 12 inch box and 1 inch drains. It looks so much nicer to work with having them spaced like that. My next issue is placing the overflow. Center back of tank or on one end panel. I'm swaying towards having it at the end this way when I put food in at the opposite end its less likely to get sucked into the overflow. But its more dependent on which tank I get. There Isn't much selection locally. Trawling the classifieds is one of my better options unfortunately.


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