Deciding on how many tanks to have is a big question for anyone starting a float center. Answering that question can depend on factors ranging from the philosophical to the inescapably practical. It really depends on what you want out of a float center. If your vision is to have a float tank perched atop a mighty redwood, overlooking to bountiful beyond, well then you probably only need one (and some sort of salt elevator). If your goal is to float the entire football team right before the big game, you’re going to need considerably more.
Within these extremes are where most people lie. I think it’s always nice to have at least two float tanks. As ironic as it is, when someone wants to experience an isolation tank, they often want to come with someone else. And it actually makes sense. You get to go out afterwards, eat dinner, talk about your experience, and feel all floaty together. Having a partner in crime also seems to be key to getting a lot of people in the door in the first place.
With 4 tanks, you can handle 95% of requests from groups that want to come together. The more tanks you add above that, basically the crazier stuff you can do. You now have a bunch of spare float tanks that you are trying to fill, which is an invitation to launch interesting programs, and run great events. Float an entire cast of ballet dancers before their performance. Have entire boards of organizations float before their meetings. The opportunities really start to open up, but obviously the costs start to pile on as well.
Most people’s answer will come from financials. How many float tanks can they afford to start with. I think it’s best to always leave room for yourself to grow. Rent a building that you can put 2 tanks into, but has room for 2 more. Or 10 more!