Whats the max?

Question

whats the max gallon aquarium a sand made out of 4x4 wood can hold? 100?

Answer 1

It depends on your stand design.  Weight dispersion, support spacing, etc all plays a role, not to mention the dimensions of your aquarium.  You could even make a quality stand from 2x4s to support the weight.  Then again, you could just as well make a c**p stand from 4x6s that falls apart.