browning/yellowing edges, to tips pics available

anyone know what this is.....im running the lucas formula at 50% strength, ppm around 425 to 450, with RO water. Only other additive is hygrozyme and 8ml per gallon.
it looks like possibly nute burn, but im running pretty mild nutes, and the plants are about a foot tall now.
the browning/yellowing is only in the middle of plant down, not really towards the top, so i doubt heat stress.
any help greatly apreciated, its only showing in 2 of 9 plants.

From what i see it looks like nute burn. But from what you say those nutes are not that strong and i cant see how they would be getting nute burn. Are those plants not as mature as the others? Thats the only thing i can think of. WHat are your temps in the room is the plant getting good air flow?

llop1103 said:

From what i see it looks like nute burn. But from what you say those nutes are not that strong and i cant see how they would be getting nute burn. Are those plants not as mature as the others? Thats the only thing i can think of. WHat are your temps in the room is the plant getting good air flow?

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Temps are a bit high, around 90 at plant canopy level (just put a air condition in the room tho, so that should nock it down a bit)
getting good air flow...
roots should be getting good o2 as its aeroponic
they are all the same age....
they are all different strains tho, the one with the most browning is very sativa looking.
just didn't think 425PPM is high enough to burn the plants.
could a magnesium def cause this?
at a loss

jayww said:

Temps are a bit high, around 90 at plant canopy level (just put a air condition in the room tho, so that should nock it down a bit)
getting good air flow...
roots should be getting good o2 as its aeroponic
they are all the same age....
they are all different strains tho, the one with the most browning is very sativa looking.
just didn't think 425PPM is high enough to burn the plants.
could a magnesium def cause this?
at a loss

Click to expand...

idk only thing i can think of is nute burn, i guess i should back them up to 380ppm or so

Ya you can try backing off and seeing if the burning stops. I wouldnt think it would be nute burn at 425 ppm but it could just be that plant is very nute sensitive. I know my Big BUddah Blue cheese plants are super nute sensitive. It really all depends on the strain to how much nutes it can handle. I would say its burning casue the temps but if its only from the middle down that obviously doesnt make sense. Def. dont think its a mag problem and mag and cal problems normally come during flowering not during the veg stage. i would just try dropping the nutes a little and see how she reacts. Goodluck

need advice, what do you think of my first grow can't figure what's going on here...View attachment 2618957