wtb internal overflow

Drill it on the side and forgo the box all together. More room for corals, less surface to scrape and money in the bank. I don't know that u can even buy them...

 

Drill it on the side and forgo the box all together. More room for corals, less surface to scrape and money in the bank. I don't know that u can even buy them...

 

I don't think you can drill the bottom glass, I believe it's tempered.

 

Actually the bottom glass on most 40B tanks usually isn't tempered but it starts to get a little hit and miss around that size.

Here's the Aqueon chart for example:
http://www.aqueonproducts.com/assets/011/19784.pdf

I agree with mfisher, go through the side and save precious floor space.
If you want to add a box I would suggest something similar to the 40B I did last fall...a small surface skimming box on the inside that feeds and external box through a couple bulkheads that hold it all together.

 

http://s282.photobucket.com/user/mnabryant/library/Jon

 

I'll be damned, I guess I thought they all were.
Thanks for sharing the link, it will come in handy in the future.

 

Would that work just like an Overflow box? Do you need a J tube with it?

 

Have you seen how hung's tanks are plumbed? Just a bulkhead and a pvc 90. Extremely simple. Mine has two acrylic boxes with a bulkhead in each. One is primary and regulated with a valve to minimize noise, the secondary has no valve-intentionally noisy. If i had to do it again, id just go bulkheads and 90s. Easy, simple, SMALL FOOTPRINT. In a small tank like a forty, space will be A premium!

 

You wouldnt need a j tube, but could. A valve is a very simple way to quiet it.

 

It is an overflow box, you just pass the water through the back instead of the bottom. One benefit to a box is the good skimming you get of the water surface...but as mfisher is pointing out there are endless solutions available. Keep in mind that silicone doesn't really bond acrylic to glass thats why the boxes are held to the tank with bulkheads in the example I shared. If the back is painted black that little internal box all but vanishes and it's low profile doesnt cast a shadow down to the sandbed.

Internal box in that 40B was 8" wide, 4" tall and stuck out 2" from the back of the tank...very slim.

A double drain in the external box is the way to go. Short standpipes of some kind can keep the overflow level above where the bulkheads go through the glass and a valve on one of the drains will help keep one pipe full and quiet and you dont hear the water moving to the external box.

It's just a matter of preference /DesktopModules/ActiveForums/themes/_default//emoticons/smile.gif Drill another hole somewhere for the return while you are at it /DesktopModules/ActiveForums/themes/_default//emoticons/wink.gif