Yellow leaves issue. Recevied these as clones not sure what week they are in.

First time grower not sure at this point where they should be feeding wise. Currently once per day 600 ppm ph 5.8 or so. temp is at 78 - 85 with fan blowing 18 on 6 off

They dont look so hot.

hot is right...looks like there drying up from not enough water or the lights are WAY too close...could be nute def too...probably that. There's something here about nute def somewhre here...just serch it and look for what your plant looks like to what it describes