weight 120 gl tank

Netmax..... remember I had told you we were getting a 120 gl tank? My
husband wanted me to ask if you by chance would know the weight when filled?
Is it 3 lbs per gl of water?
We are going to try and set it up in the next few days, but we are trying to
figure the best place in the house, I was going to put it where I have my 55
gl, which also has a 29 gl and a 10 gl below it, but I guess since the
weight is spread out between three tanks it would not be the same thing...
I know you said put it the opposite way the supports go, and he is going to
reinforce with a "T" below it ....in the basement. Any web pages or anything
I can get info?
thanks Nikki