Hayward, Pentair, and Jandy/Zodiac all reduce the power to the cell with the use of an automation system when going to spa mode from pool mode. If you don't have an automation system, turning the cell off or to it's lowest power setting is a must. Add this to your list of pool/spa mode operations.
Scott
Added: I am assuming you have a brand that matches your automation. A Mix and Match may leave you wanting.
Scott
Added: I am assuming you have a brand that matches your automation. A Mix and Match may leave you wanting.