Another option for you to consider--call an engineering firm in your town who can tell you exactly what is meant by "built to Florida hurricane code", and whether that means it can handle 3500-4000 lbs of weight in an 8 x 2 foot area of the floor on a second story.
I'm not a structural engineer, but I'd say that Florida Hurricane Code probably doesn't say much about the ability of the floor to handle an amount of weight.
BUT, I would also say that it is perfectly reasonable to SUSPECT that your floor
COULD support the weight of your tank. People have waterbeds in high rises, big custom fish tanks in high rises, I've seen very large fish tanks in second story bars.
I think it's well worth a couple hundred bucks to pay an engineering firm in your town for 2-3 hours to take a look at it and tell you what they think. They'll know who to call, how to get the plans, what codes the builders followed when they built it, etc. And they'll know how to calculate the volume of water in a tank, and whether floor can support it.
You could also ask the developers to tell you who the Professional Engineer (PE) is who stamped the construction plans. They start talking about meeting "codes", that means an engineer somewhere had to certify that. That PE knows and would probably tell you over the phone if the floor can support a ton or two of water.
This is not a big deal to answer this question for the people who built the building, designed it, certified and inspected it. The problem you're having is, you're getting the run around from the construction company/developers/somebody.
You're gonna have to "get creative" to "cut through the friction" of dealing with these guys. You might have to use some "social engineering". Call on the phone and raise hell. Or call up and create some rapport with the receptionist. Or bring lunch into their office.
Another idea is have your brother in law who's an attorney call down there, or write a letter. Make it sound like there might be some legal reason for the call--title work, collections. People think it's their job to do something, they will. People think they're being asked to do something extra for some guy they've never met, who's calling over the phone, they typically won't.
Another idea is to actually go down to the developer's office, and talk to somebody about it face to face.
Or, you could talk to the real estate agent/salesperson who sold you the place. They might help you with this, know some of the players, etc.
Big fish tanks require us to improvise sometimes.
