I'd imagine it would take a really big and solid person to bump and move a tank set up in such a manner.Even 3 high, that looks like someone could bump them or a small quake and they're going to pancake.
All 4 sides of the cinder gets shimmed rightJ jaws7777 this setup your running for a long time? That size tank either cinder or milk crate will work. I had my pup setup for at less a year before I broke it down. Cinders are heavy to move but not milk crates. If floor isn’t leveled a lot I lifted it alone. If more than 1/4” than shim it with composite shims. Enjoy and good luck.
Or one really hyperactive kid.I'd imagine it would take a really big and solid person to bump and move a tank set up in such a manner.
That's a lot of weight between the bricks and the tank but I guess the right sized kid could topple it.Or one really hyperactive kid.
I would level the blocks 1st than put tank on and level that. If tank not sitting even by 1/4” than shim more to level the tank but always level the blocks 1st. Try not have the tank sit twisted which will cause a lot of stress to tank. If not leveled from front to back or side to side very little I would just leave it (<1/4”)... all my setup I shim them so all tanks sit front little higher so god for bit anything its not falling forward.All 4 sides of the cinder gets shimmed right