My original LED fixture for my tank I built a few years ago and it is built out of square aluminum tubing and has fans that draw air through the tubes to cool it. I got tired of it and there was far to few LEDs on it for my reef. I am building this water cooled copper fixture that has twice as many LEDs on it. The water will flow through the copper tubing to a DIY radiator through a pump and a water flow switch that turns on the lights when the pump starts. It is almost completed. Here is where I stole the LEDs from.