I just inherited a spa shell. I have no idea what make, model or size it is. It has four seats and is only 26" deep in the center. The only thing it has is four jets and 1 1/2" piping, no pump, heater, filter.... So I pretty much have a clean slate to start with. I am planning on buying a skid pack with a 4.5 hp pump adding quite a few more jets (15 or 20). My question is this: since I am putting in a whole new skid pack, should I go with the 1 1/2" pipe or 2"?

Thanks,
Troy

it's always best to use what the spa pack uses. some are 1 1/2 and others are 2. Also, figure 1/4 horse per jet, so a 4.5 HP pump is good for 10 jets, ideally. Keep this in mind as you may need to invest in a second pump if you want to go crazy with jets. If you use the smaller jets that you often find for the neck area, you can get away with 2 jets per 1/4 hp. Dont forget when you plum the jets in, you want to make sure that you have the air lines hooked up as well, and put an air orifice (adjustable) at the surface of the tub for each 4-6 jets.