Check the listing for details. ECINU CO2 Digital Control Unit with Regulator EG-401R, Aquarium System. Condition: Used. Listed at 650.00 USD. Like New condition - Open Box (All items included into original retail packaging, except 2 small bottles of Ph Buffer) Retails $785+ EG-401 which creates the optimal aquarium environment with PH sensor connection and scheduling. EG-401, CO2 automatic control device recognized as a the patent in Korea, USA and China. Connecting the amount of gas supply and measurement to the IOT technology enables active control, creating an aquarium environment with the best conditions. Features & details Linked with Calcium Reactor pH- This CO2 digital device with a pH controller acts as a calcium reactor for coral to grow. CO2 is very important for plant photosynthesis. It can be used for planted aquariums and calcium reactors. Through the pH sensor, it can be controlled by the aquarium condition. Patent and guaranteed equipment - This CO2 control device for Aquarium Management has been recognized as a patent in countries such as Korea, the USA, and China. The patented carbon dioxide control unit connects supply and measurement to make the aquarium environment in the best condition. Precision quantitative – This CO2 digital equipment supports exquisite control based on CC/M. Unlike other devices having bubble counting or minute counting, this CO2 control unit brags the most precise unit control with CC/M like 0.1cc, 1cc. Easy menu operation – Tap the screen lightly to operate several modes to manage your planted aquariums. With the simple menu, you can manipulate the given modes, such as pH mode, pH setting, Timer mode, and timer setting. This 4.3-inch LCD monitor offers precise control. Easily move the pH scale up and down with your light touch. Aqua scaping – For the perfect aquascaping, you need to supply CO2 to improve their growth. Add more color to your aqua world. Make greener and healthier planted aquariums for your hobby. You can schedule the CO2 supply time according to your preferences.