Originally Posted by 1journeyman
Actually rule is 1-2Lbs. per gallon.
Like some other "rules" in this hobby however, this is a general guideline... It will depend a lot on what you are stocking in the tank, type of substrate, and the type of rock you use. The more porous the rock the less you need.
I agree with 1journeyman....the denser the rock such as florida, fiji, the more you would need compared to Solomon, or Tonga, and alot is what is full and looks good to you....