Hi Martha, that is a great question.

We at Techo-Bloc are the manufacturers of the Blu60 slabs and the Bullnose coping so we can't comment on the hot tub installation.

There are probably plenty of hot tub and pool manufacturers on Houzz that can answer this question.

Most likely this is not a hot tub, but an inground spa. A
hot tub is portable. You can find a pool or spa builder in your area or a hot
tub retailer nearby by visiting our member locator. Here's a great place to start if
you're considering purchasing a hot tub here's a great site where you can find information on Buying a Hot Tub.