Thanks. No thanks. Yes. While PoolSean is the best on it, I think 50% to 100% greater than your pool's size (16k) is more than enough. With some, like mine, you can mix and match controllers and cells to get the ideal setup. If I were to decide to, I could put a bigger capacity cell in my manifold and just re-set the controller to run it. This unit can also act as the pump's timer, and, I believe, select between high and low speeds, but I didn't mess with what was working fine. It can even run an acid injection pump, too. May also brew the morning coffee, but I have not gone that route yet....