This is a simple, easy to use controller / timer for your Koralia Water Pumps, just plug it in and connect to the pumps. There are two channels, each with an output of 100W, enough to operate 2 larger pumps or 3 or 4 smaller ones with a splitter. Programmable settings allow you to set times between 5 seconds and 6 hours, and can be alternate or synchronous. With such a wide range of time intervals, you can create a wave effect or a tide effect, or a combination of the two. This versatile controller allows you to program one or both feeds.