How far apart are your joists? 16" on center with Trex can give a liitle with the weight of a tub, you may want to add another joist in between existing where the tub is going. Are the posts 4x4 or 6x6? How far apart are they? The Jetsetter is 105 lbs per sq. ft. if you make a drawing of your deck and take it to your dealer (i'm guessing Mainely Hot tubs) they will have the answers for you. If you go Solana TX, it only weighs 75 lbs per sq. ft, so you would be fine if built to code. You get more jets and power with the Jetsetter, wet test the lounger - it can be uncomfy for some taller people. I have the Solana and love it.