Need a little bacK up advice!!!!!!!

so i just started growing for my first time im doing hydroponics and currently have my girls in 4in grodan blocks getting fed three times a day on a drip system for 15 minutes each feeding....what my main concerns are two of my plants have yellow around two different leaves on the edges what does this usually come from?and how can i fix it? the nutrients i am giving them is cns17 which i really dont wanna use based on my research its not the best...so if anyone could help me out that will be really appreciated i have piks if u need to see em!!!!!!!!!!!!!!!!!!1

Greennerd...thats not nice! He is new here & this site is to help & be helped. Sorry bro, for his rudeness. Pix. of course r helpful, but I am not familiar with some of the things mentioned. Like the nutes. And I don't want to give u wrong advise, Yellowing can be nitrogen def., so u might want to check on that. Good luck & hopefully someone can help u. Peace & Happy gardening!

heres sum fliks thanks for the replys

Hey bro I see something you might want to change, your reservior shouldn't be clear. Light not good. Peace

yea i got 20 gallon tub totes for my reservoir but i jus hooked m drip system up earlier today....i gotta quick question tho i jus put them under a metal halide lamp from fluros how far away u think it should be from the plant?

Voo, here's a link for you. It really should cover a ton of questions you probably have. I personally refer back to this page often. https://www.rollitup.org/newbie-central/1326-101-already-asked-questions.html It may not have everything you are wondering, but it definitely covers your question regarding lighting and nutrients.