retail $135

One of the smallest all-inclusive auto top off systems on the market today. The Micro ATO includes an optical water level sensor to keep an eye on the level within the sump with no moving parts. The optical sensor is very reliable, even in complete darkness, keeping a steady water and salinity level replacing any evaporated water with fresh water. The Micro ATO, like its predecessor, uses a magnetic mounting solution that works for tanks and sumps that have up to 1/2" thick walls.