is this nute burn? pics

hi guys got 4 plants the new sets of leaves have slightly yellow tips is it nute burn? there just under 4 weeks old been feeding them bio grow quarter strength only had 2 feeds with it in last 2weeks could it be anything else

look pretty healthy to me

I would say no but if it starts to get worse and the yellow comes from the outside of the leave twards the center you were right, flush very good with tap water.

Also little discolorations like that can be just from natural conditions in your area and is normal but when you see lots of discoloration,droopy ness,or wilting you are prolly doing something wrong but your crop looks fine to me.

thanks guys hopfully wont get worse i didnt think it would be nute burn as they havnt had a lot