styrofoam under tanks
 

My new 180 has arrived! I built my stand and have checked it for level and square. The tank I have has a flat trim on the bottom not the trim that raises the bottom pane of glass 1/2 inch. The bottom pane is only raised the height equal to the width of this flat trim probably 1/8 of an inch. So I want to know what I should place on top of the stand between the stand and tank.
Couple of ways I have considered and have been searching online about.

1) I could place the tank directly on the 2 X 6 rails nothing between tank and stand with open top tank.
2) place plywood on rails and tank on plywood
3) place 3/4 styrofoam on rails then tank on styrofoam
4) place plywood on rails then styrofoam then tank

Any suggestions which way would work best or what way do you have your large tank placed. Take in consideration the type of trim on the tank. Thanks
Please post with anything you have experienced. I know it has been debated a lot but I want to do it right.

Option 4, plywood, foam, tank. Double check plywood for level prior to adding the foam.

I use 1/2" rigid styrofoam under all my tanks, I don't like to use thicker stuff. Sometimes I have to look around to find it with straight edges instead of beveled edges, but I can usually find it at Home Depot. The stuff I buy is Owen Corning "Foamular". I like the styrofoam to stick out around the tank about 3/16" all around, so since your tank is 24" wide I would cut the styrofoam down the middle of the length and leave a little gap in the middle so it can stick out all around. Using plywood helps to strengthen the stand if there is any doubt, but usually is not needed if the stand is well built and the edges line up nicely. Although if the bottom pane of your tank ever breaks the plywood helps to hold the water in a bit while you're panicking to get everything out. :D

Is this what you have for your tank?

Thanks Myka. From what I have been reading the opinions are foam under tanks without a trim and no foam under tanks with a trim. The trim I described in my first post is not the "normal" trim that I have seen on other tanks. The bottom pane of glass would almost be resting on plywood if I used it. So would this be considered trimless? Tanks only need to be supported on the outer edge correct? I'm thinking if I use the styrofoam without the plywood it would even out any imperfections in the 2 X 6 while not putting upward pressure on the other sections of the bottom glass. Anyone see anything wrong with this? From what I can tell the sides of the tank are sitting on the bottom glass. Thoughts?

Option 4, flush with tank edges, 1/2" pink.

I was hoping you would reply. This is what you recommend on your stands? I realize yours are metal.

I use foam under both types.

This is what I do with ALL my tanks regardless of how there made. Wood or metal I use 3/4" plywood on the top , then 1/2" ridged pink styrofoam. I like to put a molding around the bottom of the tank as well to hide the foam & bottom edges of the glass.

Good info thanks.I was thinking I would use foam just wasn't sure of which option. I have the white polybead styrofoam I guess I'll pick up some of the pink rigid tomorrow.