Weighted float switches on SO cord is acceptable. In fact that is all I've seen around here. Nasty job! If you're using multiple pumps, I use an alternating relay to switch pumps every time. For instance if you've got two pumps, the longest switch will turn on the relay which brings in a pump. If one pump can't keep up, then the next longest switch will bring the second. If they can't keep up the next switch will bring in a alarm of some type. Hope this helps.
