leaves are a burnin'

[solar72]

i thought this might have been heat stress but now im not to sure

3 weeks into flower
ph 5.8-6.1
ec 1.57- 1.64

using hydro ionic bloom & boost, anyone use this before and if, am i using the right amount

400w hps

what is the probs - to all experts out there

 

[bake508]

how far is ur light from plants? i put my 400w no more than 17-20 inches away and i have a fan blowing air up at light

 

[solar72]

how far is ur light from plants? i put my 400w no more than 17-20 inches away and i have a fan blowing air up at light

hi bake
there roughly 10-12" from tops
i also have a 400w and last night i put a fan in blowing at the light to see if it will help.

been doin a lot of l.s.t. because the are growing fast and too close to the light as the light cannot be raised any further.

 

[RickWhite]

Same thing happened here. I think the boost causes toxic levels of P & K. My leaves started to go yellow with burned spots suggestive of nut deficiency (or toxic lock out). I'll never use Boost again.