Problems with leaves in LED grow

brotherjericho

Well-Known Member
Interesting. I supplement with Cal/Mag every watering, and it has a small amount of iron as well. My plants seem to be doing well under a PG180, only one plant shows yellowing but it is only in the oldest fan leaves that come off of the main stem.
 

kang420

Well-Known Member
Yes cal-mag can help but if you require alot of iron using a high powered led cal-mag may become a problem as too much calcium can be toxic when you only need to use iron, i was thinking of going back to hps full time until i seen the wonders iron can do
 
Lights are to close to the plants and its has bleached the leaves and now they are dying from bleached leaves...seen in many times until i figured out and corrected it by putting LEDs 24+ inches away. By the Way do the panels you have have lots of blue diodes? if so this is defiantly the issue..also to much light for veg with leds can be to much absorption for plants. i recommend on avg 5000-7000lm.
 

PetFlora

Well-Known Member
Lots of good 411 here, plus some really bad: 'flush with full btl of H2O2' WTF? :wall:

Here's another thing to look at, early on you mentioned a nute with a ridiculously high P and very low NK. Even if it is an additive, high P is a plant killer by itself, AND in those ratios it would lock just about every other nute out.

PPMs is another thing. From what I've read, LEDs only need about half the nute strength, and most people mix too hot (I used to be one of them). At full throttle flower I use ~ 1000-1200 ppms

You are right to switch to aero/hydro as screw ups can be quickly addressed with some flushing. I have brought plants back from the brink of death.

I recently switched nutes to a one step dry mix HR V & B, and am so happy with the results, and especially ease of use.

Since you dais you check pH, last grow my Hanna probe was dying and giving false reads. When I got the new probe calibrated I found my actual pH was <4! The plants were burning up from the inside out. I was able to salvage the plant because I use hydro
 

cannabuilding

Active Member
I completely agree with petflora above post, well said.

I've learnt the hard way here to, was feeding way to much canna coco ab at 1.5 ec, turns out the plant only needed a max of 1.0ec.

Combining to many flowering additive/enhancers/hormones at one given time will 100 percent cause nute lockout at some point.

I found that adding earth juice catalyst to every watering in flowering really helps (1ml per 1L), and has stopped alot of the yellowing leaves, and really adds to flavour and res production.

Peace to all and happy growing.
 

okcomputer

Active Member
I take care of the overfeeding problem by using a very light soilless mix (roots organics greenlite) It drains fast, aerates well, and still holds moisture for a few days. I can still give a full strength feed though because most of the solution will drain out the bottom in a few minutes.
 
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