I'm running a 230g with 100g sump. My stand is made of angle iron steel. Frame sits on a rubber mat on concrete. The inside of frame as 1/2" layer of styrofoam on bottom against the rubber and a piece of marine grade plywood cut to fit inside of the steel frame. I'm short so I thought this would be great for me. It's extra work!
It is a pain in the rear to vacuum floor of sump..not just siphon difficulties but it's hard to see where you have cleaned/siphoned unless you are on your hands and knees watching where you have cleaned! The length of my sump makes it more time consuming (72")! When I redo the tank, the sump will be raised for better access.
Unrelated to sump on floor......but worth mentioning! I have had stray voltage in that tank for 3 years. We've had two electricians(licensed) to try to figure it out. All outlets were inspected and grounded properly. All equipment was isolated and tested for shorts. I tossed 1 circulation pump (via-aqua) and I replaced ALL my heaters. Both electricians said current was running through the concrete and it would be impossible to remedy. We also drove 3 copper rods in ground near the box where electric comes into our home. Then grounded the rods to electric box. No change, I still get shocked if I come in contact with steel frame or if I touch the side of my ladder when I am working in my tank. As a rule, be sure to wear your tennis shoes downstairs before putting your hands in the water! Not being mean...but it's funny when my dog steps in a puddle of water. They move pretty quickly and give me a goofy look! The tank has no animals in it. It's running with heat and LR only until I decide what I want to do with the tank! I really like the tank, but it's too deep for me to work in it.