Does the WaterGuru Sense work in Above Ground pools?

Yes.  WaterGuru Sense will work in above ground pools, under the following conditions:

• The Sensor unit that hangs down from the top of the SENSE needs to be completely submerged in the water in the skimmer.
• Pool skimmer - The WaterGuru SENSE fits in the 8-10" circular above ground skimmer opening. 
• Pool skimmer must be mounted high enough to allow enough clearance so that the bottom part of the SENSE cover does NOT come in contact with water in the skimmer. The SENSE cover contains the power supply.  Contact with water should be avoided.
• If the SENSE cover comes in contact with the water, the SENSE may eventually stop working.  Such usage is not covered under the warranty and will void the SENSE warranty.