Brown/yellow curling leaves

I've got a crop of 8 Blue Mystics. Everything appears to be going great. Roots are nice and white growing bigger by the day. Ph doesn't appear to be an issue. I check it twice a day and it's always between 5.7-6.1 the PPM is 1100 the water is distilled purchased with a PPM of 140 so it's can't be Nitogen burn right? It's onlt on 2 or 3 plant on 1 or two leaves. They are 4 weeks into veg and are 8 inches tall. Any thoughts would be appreciated. Oh ya Temp shouldn't be an issue either it's kept in a cabinet inside a climate controlled room an d the cabinet is the coolcab which has 2 fans and I've added 2. Thank you.

Well your ph is good and so is your ppm. What type of grow medium, nutrients, and type of system are you using? How long is you feed cycle?
If you can post a pic I can help a lot more.

Yellowing is low nutes id say your best bet is a nitrogen supp grotek has a 3.0.0 solution i use.