This is my first time doing any of this and it's a lot to learn. Setup is a 4x2 tent in a closet. Germinated in paper towel, then dropped into coco pucks (first 6 in coco, started 4 more 2 days later in Rapid Rooters), then into tray/dome once taproots were out. After sprout, took lid off and removed heat mat and put under 18/6 at about 50% power and 30 inches. There's a lot going on in those two sentences, and I will elaborate.
Coco was a bad idea, probably my fault, but it was nowhere near as simple and successful as the Rapid Rooters. For one, the coco plugs did not fit into the tray I have, it's whatever size the RRs are. This was my fault, and caused the lower portions of the plugs to compress too hard for roots to grow, basically stopping two seedlings in their tracks. Another issue with the coco seedlings is that they started wilting and turned pale green on 2/6. After some reading, the possible culprits I found were overwatering, cal mag deficiency, nutrient deficiency, possible fatigue from too much light (I tried 24/0 for a couple of days and went back to 18/6 because of this). So I dosed them with calmag, transfered them to the solo cups, and dosed the soil and the pucks with Big Bloom. A day later and the leaves have almost lifted all the way back, and their color is getting back to normal.