I hope it’s 3/4 but to me it looks like 1/2.If that's the stand that the tank builder, built for the tank. Then it seems like they would know, since if you buy it, bring it home, set it up, and it falls over and smashes..they gotta give you a new 1. That being said, it looks like 3/4" Cabinet grade plywood, that stuff is strong when built and glued properly. I think it could support the vertical up and down weight. My concern is that style construction is not very strong side to side, it can Rack very easily with 900 pounds sitting on the top. But if you look at like the Red Sea Stands I think they are very similar construction with fancy plywood with glued/mortised joints. I don't believe they have a skeleton but I could be wrong.
These guys are coming to my house and delivering the tank and stand. They’re setting up the stand and tank, hooking everything up, testing it and doing the tank transfer (75 gallons into 110 gallons).
This is a turnkey project.