Slow first growth..possible issues? noob.

What looks to be the main issue with these plants?
growth is slow(I keep comparing these to other grow journals and these seems so far behind and slow)
First set of single seedling jagged leaves yellowed(I picked them off).
They current leaves seem to have curled down but stiff leaves, plants are just 18 days old under a mix of 6500K and 2700K 23watt CFLs a few inches away. First plant (reg seed sleestack x skunk)has 2 CFLS and 2nd plant (fem. autosomango x blueberry) has 4 CFLs on it.
Temps are around 78 and humidity around 55. pH was below 7.
I have not given any nutes yet, sprinkled some Fox Farms tomato and vegetable fert on top but have not watered it in yet, I figured it was slower, lighter and safer.
I have a small fan blowing on them constantly and they move/flutter a little all the time.
Have them on a 20/4 light schedule.
Soil is MG topsoil organic mix with 50% perlite.
I cannot tell if this is too much or too little water, too little light, too much air on them, not enough nutes.
Are in Solo cups with bottom removed and planted in larger gallon pots of same soil.
I have looked a lot of pictures to find something similar before posting this...I wanted to be careful about what variable to change first and not change up too much at once. I am reading a lot and find so much conflicting advice as a noob I am getting really confused.
Any tips on what makes sense to try first or other tips are welcome..thanks!

How often do You water ? It looks like Nitrogen related to overwatering.

I agree. Im almost certain your flushing... and MG mixes are absolute shit your better off digging dirt up out ur driveway. Also I advise against planting in those cups without the base, just cause im afraid if it gets bumped over ur chances are high to your gonna rip the roots.

Let the soil dry out its good for plants to dry out, water less, add nutrients to water not top of soil you can burn the roots that way.

Also get an ec meter so you can measure ferts in water they are 8$ on ebay no excuses.

Ok, I was watering when upper levels of soil are dry, every 3 days? But did notice that soil on bottom of pot that I can see and feel via drain holes was always still wet. The pots have a lot of drain holes. Maybe I need to let pot completely dry out than add nutes on next watering? Ph of water was 7 going in and was 6 when I measured run off from soil, using ph liquid test purchased at local hydroponics store. Thanks for your suggestions.

Don't have the fan blowing on them..u just want air movement in the garden, when they get bigger yu can start hittin em wih more "wind" to strengthen the stem..and you should prolly repot out of that dixi before you feed again

I transplanted to FFOF, dried them out and they are doing great. 'Saving' 10 dollars on the MG was an epic error... along with overwatering lessons learned. Thanks.