I'm in the process of building a stand for the 8' 300 gallon tank. I built everything as straight & tight as possible, however was having a really difficult time getting the top surface parallel & flat. All boards have some camber to them over the span of 8. I started out hand planing, and after several hours was still not confident.....so I looked up on youtube how to plane a surface with a router. It worked awesome.
I used a straight edge to cut (2) 8' long pieces of 1" plywood to use as "rails", screwed them into the side of the stand (offset with 2x4) and used my level & eagle eyesight to make sure these were perfectly parallel. Then, I made a box out of plywood with a strip cut out of the middle for the router bit. The router slides forward & backward within the box, and the box slides left to right on the rails. This allowed me to get all the framing perfectly flat under where the plywood top.
I used a straight edge to cut (2) 8' long pieces of 1" plywood to use as "rails", screwed them into the side of the stand (offset with 2x4) and used my level & eagle eyesight to make sure these were perfectly parallel. Then, I made a box out of plywood with a strip cut out of the middle for the router bit. The router slides forward & backward within the box, and the box slides left to right on the rails. This allowed me to get all the framing perfectly flat under where the plywood top.