One of the biggest challenges in reef keeping is keeping your water level consistent. As water evaporates, the salinity in your tank rises, which can quickly stress out fish and corals. That’s where an ATO (Auto Top-Off) system comes in. It automatically replaces evaporated water with fresh RO/DI water, keeping your tank stable without the hassle of daily top-ups.
ATO systems are a must-have for any marine tank, whether it’s a small nano reef or a large, fully stocked system. They save you time, reduce fluctuations, and take away one of the most common causes of stress in reef keeping – unstable salinity. Most modern ATO units are compact, reliable, and easy to install, with sensors that detect the water level and pumps that add just the right amount when needed.
At iReef, we stock a range of reef-safe ATO systems from trusted brands, designed to be accurate and dependable. Whether you want a simple setup or an advanced system with multiple safety features, you’ll find an option that suits your tank.
An ATO might not be the flashiest bit of reef gear, but it’s one of the most useful – keeping your water level steady so your reef can thrive.
