Potting-up: peat pellet to coco coir mix in Solo cup - must I first wait until roots showing?

peat pellet to 16 oz cup? no worries. it's fine without a wait. here's the problem you can potentially run into. The peat pellet will absorb a lot more water than the coco. the peat will leech water from sorrounding coco due to the properties of each. This can potentially keep the early roots too wet for too long. elevated risks. you can easily skip that first step and just germinate them in the coco in the solo cup. It's small enough for seedlings Can always fill less than full too. Watering habits do effect root growth. Early you want a good wet-dry cycle. this means you don't micromanage watering and keep it moist 24/7. you irrigate and way for top layer to start to dry -- in this case with coco when it turns color is a good signal. the weight of the cup or pot is a good signal to learn in conjunction. If you irrigate at same loss of mass, it takes the same volume of water - more important later on than with tiny pots or cups. This minimized superficial root growth. promotes deeper roots. you want the surface to be slightly drier than what is below.. the roots will turn down instead of up. it is a charactersitc of how it grows and reacts to moisture in the immediate substrate that touches it fertilize every irrigation with 10% runoff and you will never have a problem with buildup in the substrate -- can still overdose plant with concentration of your feed but one less factor to worry about when diagnosing. a seed can power itself for at least a week, but the doses typical of soilless/hydro are usually no issue and often speed up the early process. starting alittle weaker that first week is not a bad idea though. i don't know what bio bizz instructs.. some companies are bat-shit insane.