Light burn

[Alpaca]

Hi,

For the first time I seem to be experiencing something that looks like light burn?

I use 2 80w white COBs for veg, currently about 32 cm from the canopy. The yellowing only occurs at the top so I'm guessing that's what it has to be, but some of the tallest leaves don't seem to be affected at all so I'd like to check with you guys. Is it light burn?

 

[BigCube]

Doesnt look like light burn.
Looks more like the start of nutrient burn.

 

[Smoking Gun]

Since you are seeing this at the top of the plant, and it does seem that the new growth is coming in a bit light, even yellow I would venture to say its a calcium deficiency. But you really haven't given enough info to be sure.

 

[Alpaca]

I have only fed them grow nutrients once and week 5 just started, when I fed them I also added some calcium so it would seem weird for a calcium deficiency to show already

 

[jaguarlax]

I have only fed them grow nutrients once and week 5 just started, when I fed them I also added some calcium so it would seem weird for a calcium deficiency to show already

Do you have nutrients in your soil? Some will release nutes based on time not on your feed schedule.

 

[Alpaca]

Do you have nutrients in your soil? Some will release nutes based on time not on your feed schedule.

I used plagron lightmix soil for the first time. It's supposed to be lower on nutrients and with more perlite so it drains quite fast