weight limitations of a tank/stand

a question, is there a load limit, to which a tank can hold in terms of rocks, i realize they displace water, but, some stands, basically support the outside edges of the tank, and leave the middle free, while others are much more sturdy, is there a general rule of thumb ? i dont know if its even possible, but could excess rocks, shatter the glass, and fall through ?

Most rocks usually don't displace the water weight, 8lbs per gallon. The problem with rocks is the weight per sq. inch on the glass, as rocks can concentrate their entire weight directly onto a small sq. inch of glass, where as the water weight is evenly distributed.

This is where 'egg crate' comes in handy. The egg crate is the material you find in Home Depot or Lowes that is used for flourescent lighting dispersion. It's the white grid of approximately 1/4" squares, that usually comes in a piece that is 48" x 24". Just cut a piece(s) that fits the bottom of your tank directly onto the glass, pour on your gravel, then put the rocks in, and you should be fine.

Tempered glass tank bottoms are the safest, as seen in a youtube video, but it's best to play safe and use the eggcrate.

Good answer.

Try using lava rock or those new stones that are on the market today. They are made of ceramic and looks like real stone!!!! They are a little pricey but compared what could happen if the aquarium goes BOOM!, Its just worth it!!!! Slate is another way to go and it will provide ample spaces and crevices for fish to hide when carrying. Add some plants or stick some java moss in between the pieces of slate makes the look of the tank like a underwater picture!!! Try it, you will love it!!