[mayres]

Hi Sharyn -
Coir can vary tremendously depending upon the source. It is actually the discard material after the long fibers of the coconut have been used for other things - like ropes, padding, etc. The material I have purchased comes in a large brick about 16X16X4 - from Sri Lanka. When you chip it off the brick and add water it is amazing how it fluffs up. People in our orchid society typically use the larger perlite too - maybe 1/8 to 1/4 inch - it is available (along with the coir) at a hydroponic store in town. I have managed to find some of acceptable size in a Fred Meyer (Kroger) store in town - in their plant department. Also have purchased a small bag of charcoal there - which is larger pieces than I like - so I have to smash it with a hammer to break it down a bit. So far so good. :-) Yep - sponge rock = perlite (synonyms best I can determine). I only have one paph in coconut chips thus far - as a relative newbie to this my guess so far is that it might last longer than bark (after a year and a half the media still looks good) and has better moisture retention than bark. You are certainly correct about there being lots of options - it is interesting to find what works for who and try to determine why.........