I bought a stand alone, 5-person (7×7 square, 36 deep) outdoor hot tub that originally had a red wood box around it. The tub is in good working order, but the box is gone. I was wondering what is the best way to install this in my yard (not on a slab). I would like to build a deck around it, but am afraid about improperly supporting and damaging it. Should I set on level ground (concrete or sand), fill it with water and then build the deck or can I build the deck around it first. Thank you in advance for your response.