Alright
No, temps were stable. if not a little above room temp. I've kept them a couple of hours under sunlight. That's when they became upwards mobile and developed their second set of leaves. That's about it. They've been under two 20 watt CFLs 6400K for 18/6 and 24/0 in the last couple of days and there hasn't been much growth other than the stem getting taller. I spray them with water every now and then. Also I tried giving them a very mild nute solution. Aaaand they're in rockwool cubes and have been moved to 100% perlite hempy since roots sprouted out of the bottom. That's about it. I'm getting a bit desperate so I might put em under a MH if the weather stays bad outside. Man I really suck at caring for little seedlings
That's true for soil/soil-less because such media typically has at least trace amounts of nutrients (for soil/soil-less media which have a CEC). It's really a fallacy that Cannabis seedlings (or seedlings in general) don't acquire
any nutrients from media during the first couple weeks. What is stored in the cotyledons is just to give the plant a jump start so it can begin to establish a root system and get the proverbial ball rolling. In a soil-less media like Pro-Mix or even coir, seedlings could grow for up to two weeks without any exogenous nutrients. This is because these materials have a CEC and do contain some quantity of usable nutrients.
The problem with perlite is that it has no CEC; it is virtually devoid of all nutrients. Anybody familiar with Liebig's law, the law of the minimum, realizes that plant growth is limited by the least available nutrient. Therefore, if you're growing in rockwool or perlite you need to provide a solution that contains a fertilizer complete with secondary and trace nutrients.
Heat because it appears that the cotyledons are folded up taco style...on the first blur pic. Thus I can see that bulb is too close. Lift it up for the proper light cast also. You need to keep them misted as well. Good Speedy Recovery.
20 watt CFL's don't tend to get very hot. Cannabis seedlings don't need to be misted. Cannabis is not an aquatic plant and it obtains moisture through it's root system.