What’s going on here ? I’ve not seen this before

[Drpurell]

Getting these bronze patches in top leaves. 5 weeks into flower.. organic soil grow. Top dressed about two weeks ago. Have recently started dropping temps with intake fan. Using blumat to water for about the last three weeks. Is this a fade starting or a toxicity ? Test of plant seems fine photos for reference

 

[LoveGrowingIt]

Is this a fade starting or a toxicity ?

It could be a fade. I doubt it's a toxicity. It resembles a slight boron deficiency. Otherwise, your plants look great and should finish well.

 

[Drpurell]

It could be a fade. I doubt it's a toxicity. It resembles a slight boron deficiency. Otherwise, your plants look great and should finish well.

Thanks !