Sorry if you've explained this elsewhere as I didn't see your earlier post about this experiment. But are the mixes entirely the same besides the peat vs coco?
http://thehotpepper.com/topic/37763-three-experiments-in-one-testing-seed-soaking-seed-starting-mediums-and-growing-mediums/
None of the Chiltepins in this experiment have ever been fertilized as of yet. I am transplanting them, and will give them all a shot of fertilizer. The link above explains the Peat mix. Tucson Hydroponics, who I thank for their donation of the Coco, told me that nothing needs to be added to the Canna brand Coco. Keep in mind that the Chiltepins in the hydrocubes received nothing but water as well, and despite not showing photos of them up above, I can tell you that the no-soak and H2O2 pre-soak Chiltepins in the cubes looked great. The Chiltepins that were in the cubes after a GA-3 soak do not look as good! I don't have access to the pictures right now(I'm at work and flickr.com is blocked here), but I'll post the pictures of the cubes when I get home this evening.
I'm actually moving away from using Peat. I chose to use the Peat mixture of 70% Peat, 15% vermiculite and 15% perlite because I read a University of Southern Florida study that states that this is the mix used by the commercial tomato growers in Florida.
Over the past three years, I have used Earthgro's Potting Soil for my 4'x4' raised garden beds and for all of my potted plants, including chilies. I use that because it costs about $5 per 2 cubic foot bag. I also chose Earthgro's potting soil because it isn't full of the additives like Miracle Grow, or sewage sludge like Kellogg's.
I didn't use the Earthgro with my tomato and chili starts this year, as I thought that Peat would be the way to go. The majority of my starts have been and will be sold to a local nursery. Peat seems to be the most used medium for plants.
I thought that maybe the Earthgro was lacking due to it being a cheap and basic soil. However, After just a few years, my 4'x4' boxes are just loaded with earthworms! Keep in mind that my yard is caliche (it's a soil hard as cement), so I doubt the worms came from my yard. Also, I have to continuously remove grubs from my soil in between plantings. My point is that the Earthgro soil appears to be just fine.
So, now I'm experimenting with a new mix that contains 50% Earthgro Potting Soil, 20% ARBICO Compost Plus, 15% vermiculite, and 15% perlite. The Arbico compost sounds amazing to me, as I was told at their store that it contains the composted insect remains from their bug farm, and that the University of Arizona buys it by the truckload (http://www.arbico-organics.com/product/Compost-Plus-1lb/1305601).
Meanwhile, the hydroponic/nursery I sell my plants to asked me to pot some tomatoes up in a Coco Coir mixture made from the coarse Coco that comes in a brick, mixed with pumice and vermiculite. I've already potted some up in that mix, but I haven't seen anything notably different yet.