3 quick questions #1&2 stand #3 uneven ground

[importspeedman]

Good day,
I am currently building a stand for my 140gallon aquarium 72lx15wx30h, and have three questions.
1) What do you guys waterproof the inside of the stand with.
2) Where might I get it in town (Phoenix)?
3) Was wondering if I can build a frame out of 2x2s, line it with plastic, mix some concrete and pour it in the lined frame (maybe 3/4" to 1.5")to make a level surface over two different types of tile? I can use rebar if required. I will also be removing the frame from the concrete after it dries.

[NanoReefWanabe]

1>is your stand steel or wood? for steel get it rhino lined or powdercoated, if it is wood a couple good coats of kilz primer and nice coat of appliance epoxy...
2>any big box store will have it (kilz and appliance epoxy, rhino lined you will have to source at local shop)
3>i am assuming you dont want to wreck the tile under the stand so you can remove this later down the road...myself i would build the stand place it and shim it with wood shims (glue the shims together and to the bottom of the stand as you shim it...) then use a piece of trim or baseboard around the bottom of the stand to hide the gap(s).

pouring concrete into a plastic lined are will not usually work unless the concrete is fairly thick 1.5"+, it will usually shrink crack and pull itself apart if poured on plastic...plus it is messy to remove...

[importspeedman]

Thank you NanoReefWanabe
My stand is wood. You got me thinking with #1, would rhino lining be ok on wood?
The reason I was thinking of the concrete was because the floor is very uneven (maybe as much as a half inch between the two tiles), and i also want least amount of damage to the tiles as possible. Also the tiles we have are very wavy, so it will be kinda hard to shim but that may be my only choice.
Any other ideas are welcome.

[t5535]

I used something like Thompson water seal on mine.

[importspeedman]

thank you t5535