Hi Bob
The Pside-Kick kit can be used to control your well pump that is feeding the RO system. You won't use enough RO water with and under the sink unit to cause the well pump to cycle too much with the kit. You don't need a larger tank.
But the RO systems should have its own tank. It will store a gallon or three of RO water in that tank for your use. It will dump more waste water than it makes clean water, but that won't hurt the well pump with the Pside-Kick kit.
