My only coir experience has been in Earth Boxes and a few other containers. I find I need to water less with coir than other potting mixes (although I'm trying some Metro-Mix this year instead of the dreaded Miracle Grow). Even in the containers that were not self-watering, I found coir maintained it's moisture for longer, without being too soggy. I just mixed some long-acting pelleted fertilizer in my containers with the coir, and they seemed to do fine. The Earth Boxes, of course, have a fertilizer strip added at the start of each growing season.
Never thought about using the gels with coirs, although I've used them in containers in the past. May have to experiment with that this year.
