I have made an aeroponic cannabis cloner from a 5 gallon bucket, PVC pipe, and a submersible water pump. It works great. Instructions can be found here http://good-cannabis-seeds.com/blogs/diy-aeroponic-cannabis-cloner
Leave the pump on 24/7. For optimum results, a plant's roots need constant access to water. Reed this for better results in growing cannabis using aeroponics.
Depending on your budget you can design either a high pressure aeroponic system or a low pressure aeroponic system. This article will give you some info about growing marijuana in aeroponics.
I agree with Dumme. You have very nice aquaponic/aeroponic system. Do you have a filter to strain the water before it gets to the plants? I think, sprinkler heads could clog from fish waste.
LEDs are more efficient from economical stand point. You don't need full spectrum Led grow lights for growing weed. Only red and blue spectrum are needed for cannabis plants. I use LEDs and I"ve never regret about this.