Tanks can hold alot more weight than you think.
say, 55 gallons, is equal to 458.989 526 01 Pounds.
That's a fair good bit of weight.You have no worries.Over 300 pounds can be exerted on the bottom of a 10 gallon aquarium, so you really don't need to worry, just make sure your rock is stable, and you can stack tons of it.You could fill a 55 gallon aquarium with solid rocks top to bottom, and the bottom most likely will not break until you either
a) drop 1
b) put over *** of weight.
Don't worry, you'll be fine.
i dont know ne thing but just from reading cuz i broke my arm so thats all i do is sit here and read
so ne ways if you put egg crate on the bottom of your tank that will help spread out the weight and protect againts accidents like dropping a rock or having a structure but it will not protect the sides