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I would include Master Spas on your list as well. Also I installed mine with 18 inches above deck for safety and convenience purposes. The only problem is that most cover lifters are not built for this 18 inch "standard" that most spa people talk about. In fact when I started calling around to find such a lifter, I thought I was asking for a 3 headed dog by the responses I got. Good luck!
I'm not a big fan of Master but there are those here on the forum that are. If I were to look at five they would be;MarquisD1MAAX (Coleman, Elite)HotSpringCaldera.
I know this isn't Pool & Spa but how much a month to get Hydropool on that list Stuart? Steve
I'll give you twice that to have them at #3
2) # people that fit in the spa. Some tub manufacturers must assume american's aren't obese. Or at least that they don't have feet. In my shopping experience I've found that you need to drop 1 person off of the tub's max occupancy unless you want to rub elbows or, more appropriately, ankles. When you wet test, try to take at least 2 friends/family. Have they sit in seats to your left and right and see how your legs and feet "fit".