Leaf tips turning yellow

Hi All,
This is my first grow and am in need of some advice. Currently have 7 plants started from seed on 4/2. Hydro grow, dwc and aeroponics. leaf tips turning yellow.
Using GH flora series. Temps between 70-82F,humidity 30-50%, ph at 5.9-6.0, Blackstar 600 led about 12" above plants,using ro water and current ppm of nutes 510. will try to get some pics up later today.

well it sounds like nute burn, once u get pics will help more, also you just said all the grows that have water invovled which one is it lol or u are using all three for differant stages? if so which stages for which grows types? also humidity should be between 40-60 tho 30-50 isn't really to bad, im guessing the 30% is at night. if using hard water are u letting it sit out for 24hrs to get rid of chlorine

Ooops, its dwc and i am using reverse osmosis water that i let sit for a day.

Still trying to track down where i put camera, have not used in awhile. In researching issue im pretty sure it is nute burn so i emptied res and put in ro water with a little clearing agent. Will give two days then dial back nutes from the 520ppm where it was to 250ppm and see how it goes.

Nute burn,or more likely wind burn if you have a fan blowing on the plants it could be something has simple has wind burn i would check this before messing around with nutes.Also i'm not sure i understand about your light scedule they should be on 18/6 nothing will be gained from 24/7 lighting scedule.The general humidity is a little high too could do with it been around 60%.......tyke

Light cycle is on at 18/6. humidity tends to be between 30-50%.