New grower, is this bad?

Hi everyone, I am a new grower and paitent. I just started growing some clones I got from a buddy.. as you can see by some of these leaves they are starting to turn a yellowish color, 1 of them it's kinda like maybe a burn like color. I got a T5 going that's about maybe 8"-12" above clones. I water them maybe once every 3-5 days depending when there dry. the clones are on a 18/6 schedule right now. i was thinking maybe they need N but my friend says no nutrience until we move the plants to a bigger pot when they grow a little bigger. is this fine for the clones to look like this right now? is there anything i should do? i did use superthrive a few days ago which he said thats ok. so is this a good idea to not use any nutrience as this stage of growing? any good advise will be apprieciated. thanx in advance

P.s. I am using a grow tent in a walk in closet, 4x4x7, i have a very nice 4" fan attached to duct blowing in through tent then out of tent into a filter. it can get pretty hot in the closet to the tent it open and door cracked to prevent it from over heating.

what kind of soil are you using?

the rest of the plant looks healthy and ive never done clones but that leaf looks old so it could be that that leaf will just die off naturally

ahh a wiser opinion

thank u jesus lolz

half happy tree frog, and half light warrior

I'd say it's probably because it got a little burnt by the soil, happens with small roots.

should i just cut these leaves off? or just wait and see what happens? if all of this is fine then its a big relieve off my chest lol

o and i have another question also, a little part of the cube from the clone is showing in the plastic cup, is it ok to add some soil to top it off? or should i just push it down as safe as i can?

I leave them, unless they start to really wilt down.. otherwise they will generally clear up as the plant gets bigger.

thank you sm315, any advise on the clone cubes anyone? or extra advise on all this?