Hmm, now the peat and coco are looking quite different. The coco plants have thicker stems, but they also look like they could still use a bit higher EC.
On day 14 I watered the peat plants and did some defoliating, that's what you can see in the pictures. There's not a whole lot to see yet, but I really like this plant already. I'm having positive experience with coco.
the peat plants got 1.7 EC water with 2.2-2.7 EC runoff (1100-1350 ppm), 6,5 ph
The coco plants got 2.0 EC water with 1.4-1.7 EC runoff (700-850 ppm), 5.5 ph as per the recommendation by plagron