I wonder the same thing, couldn't find a guide for a recirculating system, do you know any @abadtrip?
I was thinking about a drip irrigation system with recirculating water for coco. I treat my coco a bit like soil but read a lot about treating it as a hydroponic system (and it is!) and that it should be watered more often. Couldn't find a clue about recirculating the water, it's a change for a drain to waste system basically (that's expensive) and with a scrog setup works pretty good. Thought about using a diary watering system with coco that setup a timer with enough ajustable quantities to keep them moist throughout the day but I don't know shit about it and dunno how could I do that without overfeeding the plants and stuff... Someone knows where to find info?