Most of the brands out there are pretty good. A brand I would not recommend is
Roots Organics Coco Palms. It fried my seedlings a while back and I wondered why. Did a slurry test and it's salt content was above 2.0EC!
1.My hydro store changes juggles a few different brands so I never have the same one but generally use one of these 3:
I prefer 100% coco with no perlite or any other additives at all. If i had to buy a mix because I absolutely could not get 100% coco then I would settle for nothing less than a coco/perlite blend. Any other amendments are unnecessary IMO but perlite is about the only thing I'd still feel okay with in the mix if I really really had to.
If you find a different brand or really want to be sure the coco is good a slurry test(just a small glass 1:1 ratio of distilled water and coco) with an EC meter isn't a bad idea. Also when the coco is saturated I squeeze it in my hand and it should want to bounce back kind of like a sponge. That's a good sign it's not too broken down and still holds a lot of air within.
2. Loose is much easier to handle but it costs a lot more and is typically already buffered with cal and mag. I've hydrated
botanicare bricks in the past and that's probably one of my favorite bricks. It's nice and spongy. I heard canna started or has been doing bricks. I'd imagine those are of excellent quality. Bricks work just fine and definitely save money if you are willing to do a bit of extra work hydrating them.
3. You can use a mix of coco in soil, but that will change your whole nutrient approach. It will be more of a medium amendment for texture and consistency like peat moss and you won't get the full benefits it has to offer since you will be trading some of it for soil. An example would be a loss of the ability to:
- Water daily therefore introducing oxygen to the roots more often
- Accurately Judge and change how much nutrition the plant is getting
It's not a bad thing at all to add coco to soil grows in place of peat moss but if you want to utilize coco coir to it's full potential then I'd recommend using a quality hydroponic nutrient and coco just by itself.