Leaves drying out during flower

Could use a little diagnostic help, please.

This Mazar plant is 5 weeks 3 days into flowering and about 15% of the fan leaves are exhibiting dry patches. See the pic.

Other info:
Hydro/DWC
20 gl reservoir
total ppm 1350
ph 5.7
Lucas
KoolBloom Dry (1/4 tsp per gl),
Flouranectar (10ml per gl)
CalMag (5ml per gl)

I'm not sure exactly what it is, any ideas?

Thanks, YGB

Have you looked at the underside of the leaves with a magnifying glass? Could be pests...

I'v never seen that to be honest, how do the roots look? Healthy? Slimy?

Looks like nutrient burn to me.

Are the dry patches crispy?

robotninja said:

Have you looked at the underside of the leaves with a magnifying glass? Could be pests...

I'v never seen that to be honest, how do the roots look? Healthy? Slimy?

Click to expand...

Thanks for your reply.

Looked at the underside of the leaves - No critters.

Checked the roots, they look great and the tank smells clean. No slime.

I'm so confused -

Maybe nute burn then, the edges look like they are curling downward. Classic sign of nute burn.

Try flushing with plain tap water (ph'd at 5.7 or whatever ur running) for a couple hours, then dump and fill with a lower ppm. Say 900 or so? See how they respond.

ppm may be too high

Thanks all.

I was thinking nute burn but 3 other plants (all sativa not indica like this) are on the same program and there's no issues with them. In fact the ppm is even higher with them.

But, ruling out everything else, nute burn seems like the most likely.

YGB

RIU rocks! Great community!