With huge features jammed in a tiny package, the Duetto 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...

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...

Replacement dosing pump with low voltage 3-12V DC for osmolator.Power with 4mm hose at 11V: 0.9m – 110/h, 1.4m – 80l/h, 1.8m – 58l/h, Hmax 3.6m.

Why purchase a separate and expensive auto top-off system when HYDROS can do the job for you? The HYDROS Auto Top-Off Kit comes with everything you need to use your HYDROS device (like the Control 2 or Control 4) as an ATO system...

The Reef Breeders Prism-ATO  is designed to work with aquariums of all sizes, from pico desktops and All-in-One aquariums with limited space, to large reef tanks with full sumps. The Prism ATO has 3 sensors and registers your water level in a...

HydroFill Ti – Universal ATO Return Bracket The Universal ATO Return Bracket is the fastest and simplest way to complete your ATO return system. Simply position and anchor to your aquarium. The cell cast acrylic body and custom made...

HydroFill Ti – ATO Controller Automate freshwater replenishment, and say farewell to heavy lifting, unstable water parameters, and the need to frequently watch your water line. Topping off evaporated water for our aquariums is a tedious but...

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...

HydroFill Ti - ATO Return Pump Pair your auto top off with the industry's first low voltage air lift pump specifically designed for ATO controllers. Engineered for high performance, this external positive displacement diaphragm pump, outputs up to 15...

Solenoid valve to use with gravity fed water containers or with most RODI units. Replaces the stock fill pump of the IceCap ATO.  Equipped with a 14.5ft cord for versatile and easy installation Hooks up with standard 1/4in ro tubing (not included)...