Light burn? Recently switched to quantum board

[Ramborfc1]

Switched from 600hps to 600w quantum board in a 4x4 tent.
2.25ml per litre canna a and b, 2ml boost
Water is taken from 0ec to 0.4 ec with calmag.
Ph 5.9/6
Light is around 24 inches from plant tops
Some brown spots have appeared and it looks like the outer part of the leave is lighter.

 

[TreeFarmerCharlie]

That's not light burn, it looks like the beginning of a Calcium deficiency to me.

 

[Ramborfc1]

That's not light burn, it looks like the beginning of a Calcium deficiency to me.

Even with feeding 0.4ec calmag?

 

[TreeFarmerCharlie]

Even with feeding 0.4ec calmag?

It could also be caused nutrient lockout from over feeding and/or not watering/feeding until run-off.

 

[Dontjudgeme]

Switched from 600hps to 600w quantum board in a 4x4 tent.
2.25ml per litre canna a and b, 2ml boost
Water is taken from 0ec to 0.4 ec with calmag.
Ph 5.9/6
Light is around 24 inches from plant tops
Some brown spots have appeared and it looks like the outer part of the leave is lighter.

Any time I see those bronze colored spots on my leaves, it always ends up being either potassium or mag deficiency. Not saying either of the 2 are your issues, that’s just been the issue in my personal experience with my plants. Might not be a bad starting point.

 

[CannaCountry]

If you're feeding Ca, and it looks as though you're short, it's either
A) Not enough Ca
B) pH is off
C) Ca is locked out by another element