Building a metal stand

[Colin_T]

I would make the bottom section the same height as the top section. That way if you decide to change the filter or do something else, you can stick another tank on the bottom shelf and still have room to work in it.

The inside length of the stand doesn't need to be 25 inches if the tank is 24 inches, (24.5 inches would be heaps).

Is the tank 16 inches high/ tall?
If yes, you will need to add 1/2 inch for the polystyrene foam that goes under the base of the tank.

 

[Barry Tetra]

Is the tank 16 inches high/ tall?
If yes, you will need to add 1/2 inch for the polystyrene foam that goes under the base of the tank.

About 13.5 inches with 2 inches of foam

As I said I’m a bit confused with math right now.

 

[Colin_T]

About 13.5 inches with 2 inches of foam

That's fine, but you only need 1/2 to 1 inch of foam under the base. 2 inches of foam is overkill.

 

[Barry Tetra]

The tank stand is finished, thanks Colin.

Another question, what happen if I have saltwater tank on top of freshwater tank? Will saltwater drip into the freshwater below?

 

[Colin_T]

If you have a coverglass on the marine tank, it will significantly reduce evaporation and salt creep. Salt creep is where salt crystals start to crystalize on the outside of the glass.

It's unlikely any salt water will splash or drip into the tank underneath it, unless you are really careless and splash about in the marine tank or have massive of bubbles in it. Even then, a coverglass will stop 99.9% of it from going anywhere.