Deficiency or the start of nutrient burn?

[Bassguy32]

Hello everyone just wondering if someone can tell me what they think is going on with my white widow autos. They are 18 days old.
I have them growing in roots organics 707. At day 14 I gave a 1/4 dose of iguana juice organic and the week before some great white. Other then that nothing added but perlite.
they are being grown under a 600 watt mars cree 128 led in 3 gallon smart pots. Water is ph’d to 6.2. Any help would be huge and much appreciated. First auto grow don’t want it messed up.

 

[bad dragon bzzz]

looks like cal/mag apart from the edge n tip,the most common def.can we get a pic of the whole plant ?
good luck n keep er lit

 

[Bassguy32]

Thanks for the advice I really appreciate it. here’s the pic you requested. I have 3 growing of the same strain this is the only one with a few burnt tips towards the bottom of the plant.