The Nature Aquarium Control Timer from Aqua Design Amano (ADA) is a device which simplifies the automation of lighting photoperiod, aeration and carbon dioxide addition. The solenoid operates in the on position when the main outlet for the lights is on, and the outlet for air pump is inversely connected with lighting circuit, and it is activated when the timer is turned off.
Although the NA Control Timer is designed for use on freshwater aquariums, we can think of many ways the relationship between the three outlets and the solenoid could be used for reef aquarium applications.
For example you could use the timer to control your main lights and refugium lights as a simple way to get some reverse daylight photosynthesis (RDP) action, and the solenoid could limit the addition of carbon dioxide to the calcium reactor at night. This fancy timer-work won’t come cheap; Aquarium Design Group is expecting to receive a very limited number of the NA Control Timer in the coming weeks but they’ll cost a minimum of $200.
Sure you could get three different timers and a solenoid for less than half of that but you’d lose any chance of bragging rights.