Im not 100% sure but it looks liek magnesium deficiency. Need more info about the medium and feeding schedule to be sure, also if you use hard warter or RO water. Check this out: Magnesium Deficiency | Grow Weed Easy
You should be able to tell in the next 24hrs. Watch the tip Sent from my iPhone using Grasscity Forum
Canna pro soil. Feed every two days with canna flores. 600w hps added pk 13/14 to it recently. Last week or so. Heat or loght burn maybe?
Check the PH of your water and the run-off. If PH is dropping below 6 at the root you could have magnesium lockout.
Its hard to tell you exactly, and those that claim to be 100% right are eventually wrong. If you read the material I posted you will have ammunition enough to fix her problems! Dont look for solutions, look for knowledge! We gave you few options.. you could either try the solutions for these problems see how the plant reacts or wait and see how it progresses so that it can be diagnosed more easily. Your plant is big, you are using a 600w and its not too close to the plant. I dont think this is a light burn, but if your gut tells you that, move the lights further also see if your reflective material is not creating hotspots. Anyways check this out too: Cannabis Light Burn | Grow Weed Easy
Good deal. That makes sense if they're drinking it or its evaporating. Usually it's people doing that cause their buddy said to. Hope you figure out the problem Sent from my SM-G900T using Grasscity Forum mobile app
Couple bowls of water in the room help raise humidity too Sent from my SM-G900T using Grasscity Forum mobile app
If that's what you water then it if probably pot. Deficiency due to ph you need to be ranging btw 6 and 7 that last .5 is where potassium at so just by process elimination sounds like this.... don't ever give same pH always bounce around to cover all the elements being used.....btw if using a soilless mix they claim you need to be around 5.5-6.8 I would always use some right at 7 to make sure you cover everything.... Also the growth with discoloration will never turn green the new growth should clear up if you have fixed..... but also it'sd hard to be exact just gotta make sure you cover all your bases