So I currently grow in 4x8 beds of pure Canna Coco and I hand water about 30 gallons, per bed, every 3 days. I can honestly say you do not need to wait for the medium to dry out before watering again. The frequent waterings is what supplies your roots with O2. Also, IMO, when running coco you HAVE to be applying teas on a fairly regular bases. This will create massive roots, protect from rot and make your coco reusable over and over..
Depending on the size of the plant, I pre-charge with 1/2 strength base nutes and full strength CAL/MAG... ppms somewhere around 700...
Coco is the shit, period. I have tried bucket systems, Rockwool cubes and Peat/Soil mixes for years but have never seen production like this before...