Blower Manifold Big

I have a used shell hooked up to my pool pump. It needs a air pump to make the bubbles and such. It is about 6 foot square . Not the biggest but probably a 6 man in size. No labels. There are 13 large jets and numerous other air ports. Not the super fancy jetted one I'm sure. Anyhow I see some dealers saying 1 1/2 pvc pipe is only rated for 1 hp air pumps. Is a 1 1/2 Hp pump going to be over kill? 110 volts preferred. It has a 1 1/2 air manifold thingy with like 10 1/2 inch take offs to start with then goes all over the place with more manifolds on the manual controls. I had to use 1 -- 1 inch pvc straight connector inside of it to repair a break but it is only 1 1/2 inches long.
Would you buy a used one or am I wasting my money you think?
It was the manifold that was broken!