which one works better? the internal or hang on? i kinda like the internal http://www.notlehs.com/reef/salt/megaflow.JPG but i dont know if it'd be harder to octo proof than the hang on http://www.championlighting.com/pics/filterpics/ADHI_Overflow.JPG opinions?

-Keith

INTERNAL!!! Much easier to octopus-proof.

cool. does it matter if i put it in one of the corners or stick it in the middle? and with this kind do i put a bulkhead behind it to drain it?

If your tank isn't already drilled then yeah you can stick it wherever you want it. The bulkheads will go in the holes, your overflow plumbing should attach to them.

sweet. thanks again AM

Drilled is definitely the way to go,though it will void your warranty.

I like to use plastic vented heads on the top, they screw into the pvc, and are fairly octo proof.

nice. i was thinkin of using some screen door material, but that sounds like it'd look a lot better. so should i have 2 bulkheads leading to my sump? one from the overflow and one just in the side of the tank?

Screen door material works well when you can't find the proper stuff. There should be lots of good parts out there to make a good looking overflow. If you end up with one of those open top overflows and you decide to put some mesh on it make sure you can remove it for cleaning.

absolutely.

I use a tight fitting sponge in one of mine and swap it out and soak it every week. So far, no problems with the octo but AM's briarius is much more curious than either my mercs or my hummelincki.