Im not a noob to growing but have any off u used perlite for ur plants grow medum?

have any of u ever use only perlite for ur plants grow medium?
If so how often should I be feeding my lady. I feed all of them Genral Organic biothrive gro formula. I fallow the directions on the bottle.
she is the only one with perlite for a medium the other ones r in coco.
she has been in veg for around 4 weeks and 4 days.
and all of the plants light sours is 1 floro tube and 3 LED spot lights. I do plan on getting a good proper LED grow light.

i use a coco mixed with perlite

Not perilite by itself. My coco has perilite mixed in it and its pretty great!