Yellow tips but NOT nute burn w/ PICS

Ok so i started seeing these yellow tips at around the onset of flower on my LSD. I doesnt look like nute burn to me because there is absolutely no browning or crisping at the tips. They are just yellow from the moment they form and continue to stay yellow. Im growing this plant in a 3 site DWC tote along with a large nlxbb and a SSH, both of which show no symptoms whatsoever. Not even the slightest bit of burn or anything indicating a defeciency.

My ph has been steady between 5.8 and 6.2 but did slip into the low 5's before my last rez change. They are 2 1/2 weeks into flower and like i said, only the LSD is affected. Temperature is good and has been throughout the grow, RH is around 65-70 (higher than id like at this stage) and i have 2 200cfm fans exhausting, and 2 fans moving air around the 4x4 tent. 600 hps in cooltube.

I do not have a ppm meter. I know I know. but i have been feeding as per instruction on the bottle when i change the rez and topping up with plain water. Straight bloom nute with an additive. I use tap water that has been rested.

So does anyone have any ideas? I have searched and searched and scrolled through all the deficiency reference pages but havent seen anything similar apart from nute burn. But it just cant be. As you can see all other plants look fine and on track for where i want them 2 weeks in. Any thoughts??









Thanks for any help in advance guys!

Well, if you're taking nute burn totally off the table, I have nothing to add.

So it really looks like burn to you? This plant stretched more than the other plants in the same tote and more than any of the soil plants. Like 6 inches plus in a week. Could that have anything to do with it? I have burnt plants before and the tips have never remained a soft yellow colour.

Yeah, especially in pic 3. It looks pretty classic to me with the very tips curling up and browning. Not terrible, just a warning from her to back it off in the future.

You're growing from seed?

early mag def. yellowing and upturned leaves in early/mid flower. see if a dose of Mg stops it.

Ok so mg or cal def is what my instincts have been tellin me allthough i havent found a picture that looks similar to mine. This is my first hydro attempt and all my research has told me to look out for cal/mag deficiencies. Even though i do use tap and not ro water. Ill add a small tablespoon of epsom to my 40 litre rez next time it needs a top up which will be tomorrow or the day after.