Best thing to do would be to have a structural engineer take a look. I'm working on my new build (180G Reef Savvy, Custom Cabinet, etc) which will have a weight of approximately 2,500 pounds. My home is typical wood frame construction and it's not designed to handle a load like that. Would it be safe without any extra reinforcements? Maybe . . . but I'm not going to take that chance. It's very possible that my floor (or your floor) would support the weight with minimal deflection initially. But over time (we expect our tanks to last many years), that deflection will increase and may create enough stress on our tanks to cause seam failure or glass cracking.
The engineer that designed my reinforcements specified that the new support columns have footings poured. We'll be cutting the existing basement floor to do this. It's necessary because the average basement floor can't take a point load of more than a few hundred pounds. If you installed proper reinforcements, but supported them with only the existing basement floor, you risk having that floor crack / shift. Certainly enough disturbance to cause a tank failure.
I'm sure my plan sounds pretty extreme to some, but I really don't want to turn our house into a saltwater swimming pool and lose my dream tank with all of its inhabitants.