I've been growing in coco for close to three years now, so I think I have a handle on it somewhat...I am gonna say that these rules work for me, and work well. YMMV, as always. I grow drain to waste, so if you're doing recirc, I can't really presume to give advice.
I'm also not going to go into nute choices and specific feeding schedules, that's something you'll have to work out for your own.
#1-Always rinse your coco before use. Always. I've seen enough salt-burned seedlings and clones to know that supposedly "clean, rinsed" coco isn't necessarily so. It only takes a few minutes and it can save you a lot of grief later.
Technique-I'm way too lazy to rinse a whole bag at once, so once I fill my container I rinse that thoroughly with clear tapwater, then pre-charge with a light nute solution.
#2-Never let the coco dry out. Nothing will make healthy plants sick faster than letting them dry out. Nute lockouts, the whole depressing litany of ills and diseases. If the coco looks dry on top but moist underneath, water it. You can't hurt a well-rooted plant by over-watering in coco. Within rational limits of couse...
Exception-The only time you want to let the coco get a little dry is when you're trying to encourage root growth, for seedlings, freshly rooted clones, and transplants for example. Even then, just a
little dry, not enough to let the plants wilt. If the top inch of coco is dry and the container feels light, water it.
#3-Feed with every watering, and water to overflow. Drainage is good, it helps remove salts. I grow DTW, and like to get around 20% as drainage every time I water. I believe that interrupting the plants feeding cycle by clear water flushing is a bad idea. I tried it and the results were invariably poor compared to uninterrupted feeding. Even if you have sick plants, flush with a light nute solution, not clear water.
Technique-During the latter plart of the flowering cycle, about 3 weeks before finish, I start tapering off on the nutes until the final watering is a clear water flush. That's the only time during the plants entire life that I clear water flush it.
#4-Coco is hydro, not soil. Don't treat it like soil, because it isn't, even if it looks like soil. If you want to go organic, use soil. This is hydro. Use hydro techniques and nutes. Yeah, I know some of you do get decent results from organics in coco, but that's for more experienced growers, not first-timers.
That's pretty much it. It's hard to go wrong if you pay attention to those basic rules. There are a lot of tricks to learn of course, but these are the basics.
Finally, like anything else, there is a learning curve with coco. Don't expect amazing results your first time growing in coco...the amazing part comes a little later
At least not the dirt around here.
