I was thinking of putting a Tunze 6205 by the herbie
And I believe the bottom is tempered

Another idea maybe is running the pipe inside the tank as it comes over by the herbie and paint it black. Then have a bunch of little opening shooting down to the end of the tank. So with a bunch of openings maybe I dont need a big width on the pipe so its less noticeable?

Or even better yet
Could I return under the overflow box and have a tunze 6205 suck in most of the return and push it down the length of the aquarium?

Would that create enough flow? Or would i need two 6205s or two 6105s

Here is example of my other idea
I think I actually like this one. But im sure someone will find a flaw. I could have it higher up the overflow box too.
http://i389.photobucket.com/albums/o...-HERBIE-V2.png

clear will be opaque in 24 minutes.

This idea has an serious reverse siphon potential. You would be 100% dependent on somehow breaking the reverse siphon with a check valve or some other method....otherwise you would drain your tank into the sump during a power failure.

Could I just not have a couple holes in the pipe at the top of the tank to break the siphon? or is it because it goes so far down that the holes wont work.

What will stop water from spraying out the holes when the pump is on or am I miss understanding something?

when the pump is on, the holes are jsut under the water, when the pump is off the holes will be above the water

Sure..that will work. As will a check valve. Put both in place. I'm just saying that I would not want to be THAT dependent on those working...because if they fail during a power outage you are talking about complete death of the tank and flood damage to your house.

The holes WILL plug up. You'll need to keep those cleaned out all the time.

Check valves get stuck open. Especially if they don't get exercised much.

My returns go over the top edge of the aquarium and exit only 2" below water line. Even if my check valve fails, there is no way I can siphon more than 2" of water from the tank. Design to be fail proof. You'll sleep better.

I would like to second the check-valve suckage thing... although I would like to say that please dont even design a system that uses or relies on one. IMO, and in my experience... they totally suck. MOST check valves (have seen many diff brands in action) fail. Stuff either gums up in them or the 'flap' if its rubberized 'gives out' or gets deformed into the 'open' shape.

Some are around that almost surely will not fail, but for me, thats not good enough. Why not simply design a system that doesn't worry about one, and simply takes care of itself hassle free, 100% guarenteed not to leak, and saves you the money of buying one. Just my opinion. (You can certainly include one if you want, but in a well-designed system, it wont be necessary).

You could terminate it an inch or 2 below where your return goes inside your overflow. Just point the nozzle slightly downwards, That could alleviate the issue of the same water coming from the sump immediately going back into the sump.