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That degree of slope will cause your spa to be off by about 2", more or less, depending on the footprint of your spa. our Optima is pretty close to 8'X8'. Not sure I'd want that much tilt- I'm sure it wouldn't hurt anything, I just prefer my spa to be as level as possible. People with spas this far out of level often ask about shimming. Just food for thought.
1 inch per 10 ft.