Tank bottom picture
 

Found interesting

http://i67.photobucket.com/albums/h316/das75/nofoam.jpg

from here

I wonder why he has the outputs on the bottom rather than the back of the tank. Anyone know why? or have suggestions, I'm curious because my fiancee dad asked me to design a corner tank that is space limited.

I can't see the photos on that link, so I'm not sure if I'm answering this correctly, but I think I know what you're asking. Tanks are usually bottom drilled for overflows. Side drilling is usually for tanks with no overflows. Unless you mean the inputs are drilled on the bottom, in which case that is really just personal preference...some people like inputs on the bottom of the tank, others don't. Those who like it, like it because there's less filtering "waste effort" in the fact that if water is surface skimmed out of the tank, and returned down below, then there is more of a circular flow. If input and output are both near the top of the tank, then you will re-filter water that just came from the sump more than you would if it was output up and input down. Does that make sense? I don't like bottom returns simply because if you have a leak you have to tear down the whole tank. Side inputs allow you to just drain the tank down below them to repair. Same thing with outputs...they are either side drilled or use overflows, either way they can just be drained down a bit in order to repair.

Got mine drilled with the 4 CL returns on the bottom corners due setup as divider (viewable both sides).

Thanks for the replys, it makes sense what you guys are saying. Although I still think I would prefer 4 side inputs 2 high/2 low for circulation.

I recognize an OM 4 way setup anywhere....

I also see that the bulkheads are installed backwards, and siliconed in. My experience is that bulkheads leak when installed that way, so the silicon is probably pretty important here.

It depends what size tank you have. A tank that is 4' or less is quite fine with only one output and one return. Put them both up high, one on the left side one on the right side of the back pane. Use Loc-Line to direct the return flow down and to the front, and voilâ you have a circular water flow in the tank! :D

i agree
 

bulkheads installed that way is asking for some trouble. a hard bump or slightest movement will break the silicone seal and dump the entire content of the tank to the ground.

Another top down picture (fr here).

http://i67.photobucket.com/albums/h316/das75/92b.jpg

Is that tile and grout inside the tank?