I live on the second floor of my building also and I have a 125, 75, and I just recently took down my 40B with the logic of if I'm going to have 3 tanks running then I'd rather have 2 75's and the 125. The only reason I haven't bought another 75 is because I'm a bit paranoid of stacking 2 75's even tho they'd fit on the stand that way. Do you think I'm being a bit paranoid or since I had the 40 running and now it's not that a 75 isn't that much of a difference? Wow that was a rant
No your not being too paranoid. I still have nightmares of my 125 going through the floor. It's alot of weight. Or even a seal busting and water flooding the apartment.
What's the stand made out of? Steel? Aluminum? Wood? Water is just under 8lbs per gallon. So between a 40b and a 75 your looking at almost 300lbs difference in water alone. So it is a big difference.
What's your floor made out of? Concrete? Wood? These are questions you need to ask yourself. Also position of the tank to the wall. Are you sitting them on joists? My 125 is in the corner of two load bearing outer walls so I know it's sitting on joists. That's where I'd put my 75 if I get it.
Then again joists don't help for a blowout or leak. XD all of these things worry me at night. Lol as I'm sure they do you as well.