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So now would not be a good time to tout Cal Spas?
After 13 years on a concrete slab, moisture does accumulate and even treated lumber rots.  Foam turns to powder, and yes, there is a  plumbing leak from somewhere within the bowels of the tub.  Now that's beyond repair.  For the record, I water tested a Coast spa this weekend.  Jets are extremely powerful.  The leg jets in their lounge seat pump both water and/or air.  Sundance's only pumps air.  Sundance is touting the fact that their circulation pump costs $.25 a day to operate, while (they say) a 4 HP pump on low speed (12 hrs a day) costs $1.33  a day.  Stay tuned....this could get interesting