I need help figuring out where/how to fit upper filter

okay, if your using the 1 piece of wood/slat by the cut out square..then simply add another allowing you enough room to place the filter between the two..then you mount straps (at least 2) attaching one end to the wood/slat by the cut out square and one end to the newly added wood/slat.
You'll use these straps/shoelaces/etc to hold your filter up..it will rest ON these straps.

You will adjust the straps until the filter sits just beneath your wood canopy..then you can drill a small hole to the wood/slat and tie it into place...or even use a small galvanized wood screw and screw the strap in place.

 

something kinda similar to this--> http://www.edmwi.com/home/edm/page_54_100/tie_down_kit___6_piece_truck_straps_w._chrome_anch.html

http://www.autohaulersupply.com/index.php?l=product_detail&p=5292

http://www.google.com/products/cata...6sJZGewQWixpy1Dg&sa=title&ved=0CB8Q8wIwBTgA#p

could even use a white/black shoelace for the same purpose.

 

okays, I think that would be the safest idea..as it wouldn't be permanent (could always remove extra slat if you were to add addtl. equipment or change what you have now)...and if you use a small galvanized screw and SLOWLY screw it into place hopefully your wood won't crack. I'd suggest putting a small piece of duct tape where you plan on adding the screw (entrance and exit point) for added precaution.

 

Sloppy Red Line being 1 Strap..2nd being not shown.

(straps under the bottom of the filter to hold it up)..if you can do them on top then even better!

IF you have to add another slat/piece of wood you can probably add it right into the larger opening and attach the other side to the front face of the wooden canopy.

 

I'm glad your relieved, but you need to be getting rest for your classes.
Classes first..fish tank project in between. LoL!

My name is Dawn (hence the Mod_Dawn)..and good luck with the tank!
Love the canopy and stand..nice color wood (reminds me a bit of cherry wood).