You'll need a timer that can control both high speed and low speed.
Until I upgrade my equipment I just have an extra set of trips for my mechanical timer. It runs from 10:00 AM until noon and then again from 3:00 PM until 5:00 PM. You might consider that for a possibility. It is not quite as efficient or technical as a 2 speed pump, but it helps. I'll shorten the cycles a little more when Winter gets here.
Until I upgrade my equipment I just have an extra set of trips for my mechanical timer. It runs from 10:00 AM until noon and then again from 3:00 PM until 5:00 PM. You might consider that for a possibility. It is not quite as efficient or technical as a 2 speed pump, but it helps. I'll shorten the cycles a little more when Winter gets here.