When to turn on backup water powered sump pump
Normally each pump has its own float switch . They are set to increasing water depths so each one comes on independently at successively higher water levels in the sump . So the first pump comes on at depth X. The second at X + 3", the third at X + 6" , etc. ( A neighbor had 4 pumps in his sump.).I suggest the final pump to switch on should be battery powered or ( I guess) a jet pump powered by water as you have. Must admit I have never seen a jet sump pump. In other words it seems to defeat the purpose of a "backup" pump if you have to be there to turn it on.