Ok so here is a little math for ya. Each gallon of water is about 8.34lbs. So just in water weight you have around 834lbs on your main tank. I will assume that the 30 gal is not completely filled, maybe about half? so that would be about another 125lbs. So here we have 959lbs in just water weight. That doesn't include sand, LR, hardware, tank, or stand. Once you add that all up, it starts getting pretty heavy for standard floors (depending on beam spacing, direction, age, and a lot of other factors).
I have my 125g with a 30g fuge placed upstairs but it also is sitting directly over the foundation, so I don't need to brace the floors.
I would suggest maybe giving it a look and see where you want to place it, and see what it looks like underneath in the basement. If it's not going to be directly over foundation or any other bracing, they sell support beams at Menards fairly cheap (around $80 last I checked....cheaper than having your floor cave in anyway
). It might not be a bad idea to pick one up and brace the area you want to put the tank just to make sure there are no issues. Always better to be safe than sorry I think.
As far as asking, I would probably talk to a home construction company. They should be able to tell you what typical floors can handle. General rule of thumb is anything over 90g, it is in your best interest to either have the tank directly on concrete, or brace the flooring underneath...like I said before, it would be a real shame to wreck your flooring, and in a worse case, have it fall through loosing everything.
