Problems with leaves in LED grow

baxterprince · May 27, 2012

I posted this in another section but didn't seem to get much help. Hoping someone can help me here....

Plant leaves browning from the outside to the inside around the middle of the plant. What could be wrong?
I just switched my green crack from veg to flower and I'm growing in a tent under 2-1000 W blackstar LEDs. The leaves in the middle of the plant have been going brown from the outside edge in and curling upwards. I thought it may be a magnesium def but I read that that usually starts at the bottom of the plant and moves upward. Any help would be appreciated.

Using GH flora bloom, grow, mirco and pro silicate and liquid gold

bassclef · May 28, 2012

Looks like N deficiency. It usually starts on the bottom but I do see it happening on the bottom leaves in the picture. Also the plant looks a lighter shade of green overall which is a sign of general N hunger. They use a lot of N during flowering stretch; they also store it up for later during this stage, so it's important. If you're feeding check the pH in case it's getting locked out.

baxterprince · May 28, 2012

thanks for the reply and yes I was thinking n or mag deficiency but these leaves are in the middle of plant not at the bottom which is why im not sure whats wrong. Everytime i feed or water i make sure my ph is between 6 and 6.2. Is there anyway this could be being caused by my leds? The plants along the outer edge arent near as bad looking as the ones right below the leds.

Nice Ol Bud · May 28, 2012

Wow I havent seen this in awhile.
Thats Zinc(Zn) def.

A typical symptom of zinc deficiency is the stunted growth of leaves, commonly known as
"little leaf" & is caused by the oxidative degradation of the growth hormone auxin.

OR
Its burned like a mother fucker from heat or overdue of chemicals.

Lets not jump to conclusions though.
An excess of Phosphorus or Copper can show Zinc def.

Whats the N-P-K value of your blooming nutes?

bassclef · May 28, 2012

I think a pic of the whole plant would help :cool:

Corso312 · May 28, 2012

did not know blackstar made 1000 watters

baxterprince · May 28, 2012

I am using GH mirco, grow and bloom and liquid gold throughout veg and flower. I just started using bigbud powder (1-17-3

. In week 5 of bloom i wil be starting cool bloom powder (2-45-2

.
I attached a full pic of a plant. The leaves yellowing has moved a bit lower on the plant but it's worse in the middle. Now most of the plants have a few yellowing leaves. Hope I can get this problem fixed soon- thanks for the input.

cannabuilding · May 29, 2012

Have you grown in that tent before? I had the exact same symptoms in a white tent that was putting out fumes, leaves had random MG like symptoms.

Or the LED panels are to close to the plants, make sure the panels are atleast 15 inches from the top of the plant.

Peace to all

brotherjericho · May 29, 2012

Could be a magnesium def. On the advice of another member on here, I've been using cal/mag with every watering under LED. My plants were showing similar issues, though mine was likely calcium. Your GH micro has calcium, but I didn't see magnesium in any of your nutes. EDIT: OK< has mag in the florabloom, when was the last time you used that?

http://growweedeasy.com/marijuana-symptoms

The edges of the leaves may become yellow or bright green and may start feeling crispy to the touch. The light green or yellow coloring may also effect the veins of the leaves.

baxterprince · May 29, 2012

I have never done a full crop in that tent before, i vegged in it once and this is my first time taking plants to flower in it. My leds are about 20-22" above the plants. I used the florabloom once a week in veg but at low amounts. Now that im in flower im raising my bloom from 3ml/g to 10ml/g and am feeding 2 times a week.

PSUAGRO. · May 29, 2012

WE can all guess (im leaning towards a mag def also)....but we need to know your PH (soil/res/runoff/etc...) before we can confirm anything/ what are your temps at??.....good luck

baxterprince · May 30, 2012

sorry for the late reply the site wasnt working for me last night. I keep my res ph between 6 and 6.2 and i just did a runoff ph and it was at 6. I dont have a soil ph tester but i can get one. My temps are between 75f and 80f. Humidity is usually between 50 and 60.

Nice Ol Bud · May 30, 2012

Or It can be an Excess of a certain nutrient. Its not pH cause that's a mobile lock up and it goes from bottom to top.
A lot of youngsters don't know this and I advice everyone to save this image to their computer.

PSUAGRO. · May 30, 2012

Okay^^^Great chart(COULD be an excess)............But I would really like you to test the soil ph.......go to HD or lowes and buy a simple ph soil tester($5)/with the two prongs and polish the shit out of the prongs with fine grit sand paper till shiny( yes it tarnishes even in the packaging), wet your soil and push it all the way down and it will give you a general ph reading(their accuracy is acceptable enough IMO) and give us a reading from it.........The tops seem fine from the pics so its not bleaching or heat stress, your temps are fine, runoff is acceptable..........Have you done a pest check????????????..........good luck

dbkick · May 30, 2012

getting the same thing here, just changed cal/mag supplement because I wasn't thrilled about the organically sourced cal/mag I've been using, dosed them up pretty good when I picked up the cal/mag, it's only been a day or so . No results yet that I can see. got two blackstar 500 in a 4by4 tent, if the yellowing continues after supplementing with cal/mag I don't know wtf to think , I'll give it one more go in hydro but if it continues I'll be taking a beating on 5 blackstar 500.

brotherjericho · May 30, 2012

For the two who have been getting this yellowing, has it been only on the fan leaves coming directly off of the main stalk? I have the same, but it is only on those leaves. The rest of the leaves that come off of branches are a nice healthy green. And only on one of three plants, a Sweet Seeds Green Poison.

dbkick · May 30, 2012

seems just all over the place for me, I just took some photos but upon downloading and viewing on the pc you can't really see the problem.

brotherjericho · May 30, 2012

dbkick said:
seems just all over the place for me, I just took some photos but upon downloading and viewing on the pc you can't really see the problem.

OK, not like mine. I know that the leaves that are yellowing on my plant are older even though they are not at the bottom, so I think mine is N def. I trimmed many of the older bottom leaves long ago.

dbkick · May 30, 2012

dunno but I've changed up everything since I found it doing this again, they did this too me last grow and it came out horribly bad. I've got another plant under a welthink wex150 but it seems a little more in the blue spectrum than the blackstar, but anyway, this plant isn't showing the same yellowing, same feeding schedule and the ones with the issue were under the welthink without a sign of the problem , put them under the blackstar and within a week or so the yellowing will start.

dbkick · May 30, 2012

I've changed up nutrients and also raised the panels, if it persists like I said , I don't have a clue. I'll give it a shot in hydro where I can control/monitor things better but I won't put too much more time or effort into these panels if it fails too.

Problems with leaves in LED grow

Member

Attachments

Active Member

Member

Well-Known Member

Active Member

Well-Known Member

Member

Attachments

Active Member

Well-Known Member

Member

Well-Known Member

Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member