I'm a (mostly) indoor grower. I used to grow in amended soil, specifically
Fox Farm's
Happy Frog and Ocean Forest, which are peat-based with organic amendments. For the last couple years, I've been in 100% coco. Here are the differences I've seen.
The soils:
Significant nutrient load. It varied, but out of the bag, the HF usually tested around 2,000-2,500 ppm runoff (4-5 EC) and the OF was usually closer to 4,000 (8 EC). I would transplant into bigger pots as the plants grew, so I rarely needed to feed base nutes. Usually once in veg, and once or twice in flower. I hand-watered when the pots got very light. That might be every eight or nine days at the beginning of a pot, and three or four by the time I'd transplant. Under LEDs, I needed to supplement calcium and magnesium through veg and into the stretch, and then sulfur and magnesium after. I found the FF soils easy to over-water. I assume that's due to the high levels of organic amendments, many of which hold onto water harder than peat alone would.
Coco:
I've been running 100% coco for about two years. I use the Canna brand, which comes well rinsed and buffered. It's probably possible to over-water coco, especially if you don't rinse out the dust and small bits, but with the stuff I've been running, it's never been an issue. 100% coco is inert, so you have to feed every bit of nutrient the plants need. I've been running constant drip fertigation with
Blumats for the entire run. Dead reservoirs, so nothing organic in there to gunk things up. It works great. No issue with over-watering. Much faster veg than my soil grows. Smaller finishing pots.
Just what I've seen. Hope that helps.