I have a question on the need for a spa blower. My son recently had a pool built and he used a different builder than the one I used. Both builders have good reputations and have been in business for many years. I noted my son had a piece of pool equipment that I don't have. After research I discovered it is a spa blower. I do not have a blower, my spa operates from the pump only. The water pressure coming out of the venturis on my pool is comparable to the pressure coming out of my son's venturis. However, my son's spa generates considerably more water action/bubbles than mine which I assume is due to the blower. Why do some pool builders install a blower and some do not? Is it merely a cost issue or are there other reasons to exclude a blower and operate the spa totally from the pump? Is the water action/bubbles for effect/show only so to speak? Any comments would be appreciated.