Actually, this is somewhat of a debate I try not to participate in (which is why I said in a previous post that we can argue about whether it's hydro later!
).Technically, coco and perlite is a soil-less mix. Some people DO consider it hydro. I simply consider it soil-less. The actual definition of hydro is that the plants are gown in a nutrient solution. Personally, I equate that to some form of reservoir. In reality, I'm not sure it's worth debating if everyone can simply agree it's a soil-less mix. Since it's soil-less, many of the protocols are similar to hydro.
