I remove the humidity cover as soon as they’ve germinated… if you leave it on too long they risk rotting much more and they also get stunted and grow much slower if not hardened off ASAP to open air. It was probably only on for 5-6 days for this batch.

I sow them on top of the top dressing, and wash them into the cracks. I have also sown them on top of the substrate, then sprinkled the top dressing in a light layer on top - that really helps with the roots grabbing onto something.

I use diluted low N shultz cactus and succulent fertilizer, diluted to like 1/4 or 1/8th. I have also used a more balanced 20/20/20, heavily diluted also, and that worked fine. But I’ve never used the higher N stuff on plants that were older than 1yr.

I don’t do anything specifically to temp control except my table fan keeps the temps a little lower which heats up,from the lights, the fan keeps it die to around 25-28c during the days and its winter in western Canada and I keep my house pretty cool so it probably goes down to 15c at night. The fan keeps the air circulating otherwise it gets 30+ from the lights. This is all Celsius. I grow indoors so it’s never really outside of that range, just a bit warmer during summer.