Healthy yellow leaf tips?

I have Nirvana's White Castle in its 6th week of veg from seed. the plants look perfectly healthy, but the top of all 5 plants have yellow tips, except its not droopy like nutrient burn, but almost looks like its a part of the plant. Is it possible its something else? or is it just a mild nutrient burn?Sorry for no pictures

There was a plant problems thread not to long ago. I know there are various "troubleshooting" guides both on RIU and google that match different disorders with their corresponding solutions.

I flushed my nutients yesterday, ran distilled water thru for 24 hrs, the adding a new dose of flora micro, flora grow. See what happens if you flush your roots. It could be signs of rootlock, or the beginnings of root rot

Better to have it and not need it, then need it and not have it

yeah i have several grow books with troubleshooting but couldn't find exactly what its like. Thanks though, i will search for it

This might help - http://www.marijuana-seeds.net/Thanks-ThankYou.htm

Pushing your plant in flower to the max around 1600ppm for me gets slight nute burn. Same as described. This is accualy a good thing in flower because u know uve really pushed your plants