that is true but in a house all that weight is distributed evenly cuz of your floor but when you have a tank that size you have to think bro you can put 30000 pounds of weight on a single 2x12 from where it connects to the ibeam to abut 2 feet away from the beam. the further away from the beam the less weight it can hold. my tank is 18 inches wide 72inches long and it weighs 1400 pounds with water sand rocks now if you where to put it in the middle of your 2x12s even with it being on 6 of them it would break and most houses 2x12s are set by 16inch increments tis also depends if your house even has ibeams some dont come with ibeams and have 4x12 down the whole house every foot, my father is an engineer. you just want to be safe man my tank sits 3 feet away from ibeam and on 4 2x12s i went to homedepot and got supports that can be adjusted and they are rated at 15k pounds of support each at max height. i set it right in front of my tank on the 1st of the 4 2x12s and the second also infront of the tank about 3inches on the 4th of the 4 2x12s this allows me to be able to set over 150k pounds in that spot without any worry or 2nd thoughts all that for 80$ is wat i spent so well worth it 80$ insurance for a lifetime is amazing...