It also depends on how efficiently the spa is plumbed. Every inch of plumbing, elbow, etc creates more friction which slows the water down. Stick with the reputable manufacturers. They will have as many pumps necessary to power their spas for good massage. Number of pumps and jets is really an overblown factor that doesn't necessarily make one spa better. I've been in one pump spas that had great pressure. I've been in 2 pump spas that were worthless.
There is a lot of sales BS in this industry. The lesser manufacturers tend to focus on horsepower an number of pumps. The better manufacturers usually don't.
