Planning Overflows

Hoods · 12-19-2005, 07:09 PM

I have a 46 bowfront that I'm getting ready to drill in the back. I'm looking for some advice on overflow placement and size. I havn't drawn anything up yet but I was thinking of putting in two 1.5" bulkheads for the overflow and two 1" bulkheads for returns.

The overflows will most likely be located about 6" down from the top and 6" apart from each other in the center of the tank. I was going to build a smoked glass overflow about 24" long 8" high and 4" deep. This would leave me 6" between each side of the overflow and the side of the tank.

I was going to drill the return lines 3" in from each side of the tank and about 3" from the top.

I'm pretty sure the two 1.5" drains would feed the sump enough water to keep up with the Mag 9 but I'm wondering if it's overkill.

I'll get some plans drawn up in the next day or so that might make this all a little bit clearer.

Any comments?

Steve

Geoff · 12-19-2005, 07:59 PM

one 1.5 will be plenty for a Mag 9. a 1.25" pipe can handle 900gph so a 1.5 is plenty. have a look at yardboy's tank setup. this would work well for you.

G~

bad mantis shrimp · 12-20-2005, 01:27 AM

What are you going to drill your tank with because i want to do the same thing. I have a glass tank. Is yours glass to?

Hoods · 12-20-2005, 11:23 AM

Yep, it's glass. I was going to drill with a dremel and some diamond tipped bits. Not the most elegant way but a 2 5/8" hole saw on glass seems a little scary.

I'll try to find the links to the info that convinced me I could do it when I have a bit more time.

Late for work atm

Geoff · 12-20-2005, 11:45 AM

i would not do the dremel trick. really ugly cuts. it is easier to hop on ebay and get a hole saw from some guy in China. i just ordered two. one was $9 the other $5. a hole saw gives a nice round cut. easier to get a nice fit with the seal.

G~

Doug1 · 12-20-2005, 03:48 PM

Dremel drilling thicker glass is a long tedious process, go with the diamond drills, use plenty water for cooling and go slow, have a lot of patience. Rushing is not good.

[quote] I was going to drill the return lines 3" in from each side of the tank and about 3" from the top.[unquote]

I wouldnt do that, it adds 2 more holes to drill, increasing your chances of a mishap, and then you have 2 more drains back to the tank in a power off scenario, unless they come back into the overflow section and you use line-loc or something to go over the overflow wier and into the tank. IME better to have the returns go over the top, with siphon break holes. Its a lot more flexible , you can move the return hose around as needed