I don't understand how a correctly setup siphon overflow could ever result in water ending up on the floor. The whole idea is that its an "overflow" so if the water in the tank gets too high, it will overflow into the stand pipe and go to the sump. The siphon just carries waterfrom the tank to the container with the standpipe, (or i've seen different pvc
joint setups that accomplish the same thing). The only danger that could result in water on the floor would be if the pumps carrying water to the tank shut off and the return line then became a siphon, but that is easily taken care of with a check valve or even just a hole drilled in the return just below the waterline in the tank.