I have heard many bad reports of recycling coco nutrient water, but some still do it with some success....
I dont recycle coco nutes, i prefer drain to waste.
I have had ph problems recycling in a drip set up but im sure its my coco quality isnt all there.
Im about to start hand watering because it holds water pretty well. I would say if your gonna recycle buy the best coco you can find for less problems.
I will be running better quality coir next time to see how it goes sence the chips I bought where very dirty couldnt get them clean seemed like a lost cause. They are alive but slowly growing we will see if crappy coco works I guess.