nute problem or mold?

ok I have a waterfarm only about 120 watt cfl , 1
plant super silver haze . I am using neptunes harvest seawed and fish and a little dyna bloom, can't get dyna grow for another week, so I think neptunes harvest should be ok till then. Anyway it is 12 days old, today I noticed scaling on the root and one of the the 1st set of leaves just turned browm, I think it might be mold, in that case what should I do about it? been keeping the ph at about 5.5

I don't know if it because I am useing a tablet but I don't see a attachment for photos, I know youl need to se them!

You don't need to be feeding them nutes this early, but until you upload pics can't really help you.

ok here is the pictures

ok so when should I start nutes? If it is mold what's the best way to go about disinfecting it ? I have a 4 by 3 cabinet so I should be able to control it right?

looks like light/nute burn pics are kinda blurry. I would definitely say its not mold tho. Start ferts at 4 weeks; use half strength or less

Definitely light/nute burn. Stop nutrient feedings until plants have developed 3-5 nodes. 12 days old is far too young to be drenching in any level of nutrients, no matter how light. In the early stages of life, the plants are getting a good majority of their nutrients from the cotyledons, and have no need for nutrient assistance. When you do start feeding with nutrients I would suggest feeding with 1/4 of the dosage on the label.

Give it fresh ph'd water only and bring the light up some, get air flow in there too.