Don't put too much thought into it. It's a medium like anything else. Watering is going to be more like rockwool then soil (pot size dependent). Brands of coco don't mater all too much. Cheaper stuff will need to be rinsed like bricks. I like Royal Gold Tupar. Strait out of the bag since it already has perlite and it's pretty cheap (10 bucks a bag where im at and pallets of it) and no rinse. Pure coir also works. Used Canna and
Biobizz purple bag for a lot of years and works great but gets crazy expensive and not worth the money. Perlite ratio is IMO at least 20-30%. The more perlite I added the better the plants did. Got up to 80% perlite and 20% coco at one point and was fantastic but that is not realistic for hand watering.
I never once buffered coco or changed my nutes to suit it. Just fed them like I do all my drip plants and it works. Not letting it completely dry it is a must. When you first transplant tho you will want them to dry some till they really start taking off. That is usually the time you can over water them. Specially if in bigger pots. Just go by weight. water when say 20% left the first couple of waterings and increase from there. Pretty much like soil the first couple of feeds. Just let the plants tell you if you are watering too much and back off a little. If you were a soil guy it might seem like you water too much but you dont.
I also feed till runoff everytime or day (if drip). I also never give Coco plain water till it's time to flush.
This comes from a hydro/drip approach. You can also treat it like soil in big pots and amend it. It's kind of a jack of all trades medium.
