IceCap Gravity ATO

The IceCap Gravity ATO tops off evaporated water using zero electricity — a simple pressure-differential design where water flows from an elevated bottle into the tank automatically once the water level drops below a short intake tube. Power required: none — works entirely on gravity and pressure difference Includes: Gravity ATO base, 3 mounting inserts for different rim thicknesses, 500ml bottle, silicone tubing Setup: pick the mounting insert that matches your tank's rim thickness, cut the long and short tubes to length (both cut at a slant), insert them into the base, thread on the bottle, and mount it to the rim. Adjust so both tubes sit in the water — when the level drops below the short tube, the bottle automatically releases water until it's covered again. Best for: nano tanks, backup/travel top-off, or anywhere a powered ATO isn't practical or you want a power-outage-proof backup. Compatible replacement parts: mounting inserts and silicone tubing for the Gravity ATO.