Can you just keep feeding it water ?
no, coco needs to be constantly feed with coco specific nutes or hydro nutes. coco is hydro-hydro is any medium other than soil. you've never used coco so, a few things must be understood coco isn't soil, it is hydro, so you should go about using it as such i.e keeping your medium wet but, not overly wet. coco is very forgiving if overwatered coco will ration water/nutrients of to your herb plant, furthermore coco retains water well if underwatered. the trick is to find the balance according to the strain. i would strongly caution mixing soil with coco because, of ph differences. soil needs a higher ph, don't really care to know because, i run with coco with a ph of 5.6 to 5.8 when watering. i think soil runs at like 6.5 to 6.8 so, preventing lockout of nutrients could be very tricky. if mixing i'd go with perlite, but, straight coco is the shit, thats all i use with a hydroton bottom layer for extra drainage as i run to waste, but, i've seen grows where they don't have any run off when they water in coco.