- Optical sensor may not operate properly in aquariums with high turbidity
n Auto Top Off (ATO) system is notably one of the most important pieces of equipment for a saltwater aquarium and simply a must have for any reef keeper. The IceCap ATO monitors and replenishes evaporated water eliminating the daily task of adding water manually just to keep your aquariums water stable. Reliable The IceCap ATO is a well thought out automated system with a fail-safe design that uses two (2) optical sensors to monitor the fluid level of your aquarium or sump. The second optical sensor provides real-time protection against failure of the first sensor. Best of all, it is very easy to install and contains no moving parts that can fail. Safety The IceCap ATO also alerts you when your top off reservoir gets dangerously low to prevent the water pump from running dry. A bright LED indicator will allow you to visually see the status of your IceCap ATO as well as any possible issues. Plug and Play You simply move the magnet optical sensor base to the desired water level within your sump or aquarium. It’s that easy! Mounts to Most Clear, Tinted or Painted Surfaces Max wall thickness: 1/2 inch (12.7mm).