Leaves dieing off during flowering please help

Its mainly effecting growth which is exposed to a lot of light though there is a few yellower leaves beneath the canopy. it generally starts with yellows spots on a leaf which often grow larger and into one another turning brown and dry, leaf tips curl up and look burnt almost. I would describe it to look like a P and K deficiency and its progressing to other leaves all the time.

The grow; Scrog, 4 Big Buddah Blue Cheese 6 weeks into flowering (7 weeks 12/12). 2x 400w HPS, Continuous drip system in clay pebbles, air stones fans etc. around 29C temp and 55% humidity. ph always around 5.5 to 6. Using Canna range of nutrients including boost and P and K for last week or so. EC in the reservoir is 2.0. They look good apart from slowed growth right and a good number of these manky leaves.

sorry for the poor quality pics

Greetings.
Gonna guess these are like 4-5 weeks old, The issue showed around week 3?
Starts on older leafs and moves up?
You are feeding them what nutes now and what nutes at flip for those 3 weeks?
Details of set up please.
OK I see they are 6 weeks. My fault.


Potassium (K):

-Chlorosis moves upwards from older leaves rapidly progressing to necrotic lesions most visible on margins and tips
-Branches easily broken
-Stems may stretch
-Similar to iron deficiency except for curled margins and tips




#Guesstimation

Look over fertilized and burning. Need leaching and lighter feed.

i agree looks overfed, not bad tho

thanks guys. so how do i like your replies on this forum?

I hadnt considered overfeeding as i just follow the canna schedule but i guess it does look like that and perhaps unlikely to be P deficiency as i use a P K additive.

I have done a few grows now. should i be following a lighter feeding schedule as i run my drip system non stop while the lights are on

No worries. You can like after you are promoted.
FYI: The canna line is low on P/K at flower start and the schedule calls for the bump like 2 weeks late.
I use canna as well but switching back to 1 part powder after this.
Glad I saw yours now so I know it wasn't just me!

Cx2H said:

No worries. You can like after you are promoted.
FYI: The canna line is low on P/K at flower start and the schedule calls for the bump like 2 weeks late.
I use canna as well but switching back to 1 part powder after this.
Glad I saw yours now so I know it wasn't just me!

Click to expand...

Just have to say. What plants need and how much is entirely dependent on the individual plant. You have to watch and listen to them. There is no perfect recipe. Every grow can be different.

so this is tough. i have to make a decision between whether its a deficiency or overfeeding and whether to flush or increase nutes.

I'm meant to be just over 3 weeks max from harvest (though i think these plants might need longer because of this stress). I normally flush for 2 weeks. Any opinions on whether it would be a bad idea to start flushing now up until harvest?

I think you should give some fresh water. Enough to run out to a lighter clearer color. Then put in a lighter dose of nutes to a normal 15 to 20% runoff.

This will likely "re-set" the medium. You can't hurt anything. And if they need more they will show it.