Auto Top Offs

For small aquariums, a stable osmotic balance is important, because they are particularly sensitive to constantly changing salt concentrations. The Osmolator nano which was specifically designed for this, is a water level controller with only a...

With huge features jammed in a tiny package, the Duetto2 is the perfect ATO for your aquarium. XPAqua’s proprietary dual-optical sensor packs two precise level sensors in one incredibly small package. In addition to keeping your water level...

The Reef Breeders Exo-ATO (External ATO) is one of the first ATO systems to contain all electronics outside of your aquarium. The controller and sensor mount to the outside of the glass, and a small magnetic ring is inserted at your desired water level...

The Smart ATO Nano Kit is a plug-and-play auto top-off system made by Autoaqua. Specifically designed for nano and pico aquariums under 50 gallons, this ATO nano kit will automatically monitor and refill evaporated...