Also Hot spring filters 325sqft of water while Caldera filters 100 sq ft.. Hs has 3 or four filters while geneva has only 1.. Does all this matter since they both have 24 hour filtration??

I hate hot springs, and have always had tubs with a single filter... cheaper to replace, work just as well...in my opinion.

Charger has a valid point, more filters = higher replacement costs.

As far as one filter being "enough," there is simply no substitute for 100% filtration, imo.

The advantage that Hot Spring has is superior filtration while the jets are being used. In my opinion, that's when it matters most, while you are using the spa.

24 hour filtration in the Hot Spring is overkill, but in spas that may not be able to filter the water as it's being used, it may be neccesary. That's not to say inadequate. Hot Spring can accomodate a larger bather load, maybe that's a more equitable way of saying it Each do fine in their own right