Help a newbie out

So my plants are three weeks old now they look like there doing great starting to smell great and there growing big very quick but three of them the leaves look quite droopy is that just me being a newbie or are they ok ? If not am I under or over watering them any help would be great one of them isn’t droopy and I’ve been watering them all the same thanks

 

Not sure the lights have been on all day so they havnt had dark time yet