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It's 420 somewhere

Brown Spots, Please Help!!

Hi all,

 

So I am doing my first grow and I am facing a few problems the same as most of us do, I have managed to stay on top of most things but yesterday I noticed a few brown spots on one of my plants.. I have read up loads but depending on the site I look at the cause differs so I thought I would ask the community to see if any of you have any ideas as to what the cause might be?

 

Auto NL

Quick overview of setup: 

450w LED (29" above plants)

75x75x200 tent

Ram carbon exhaust fan

 

I am doing a hydro grow, started them off in rockwool and now in Hydroton in a wilma drip system. sitting around 800ppm at the start of wk3 / PH 6.1-6.2 res temp at 20c with air pump.

 

Let me know if you need anything else, any help would be appreciated, Thanks :) large.IMG-20181203-WA0039.jpglarge.IMG-20181203-WA0037.jpglarge.IMG-20181203-WA0040.jpglarge.IMG-20181203-WA0039.jpg

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I don't do hydro but it looks calcium def to me, are you in a soft water area? Best to get some pics up with leds off so can see the leaf colour properly

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6 minutes ago, Autobud said:

I don't do hydro but it looks calcium def to me, are you in a soft water area? Best to get some pics up with leds off so can see the leaf colour properly

 

 

Thanks @autobud Calcium def was one of the things i came across which is why i have been trying to get the PH to 6.2 as I hav read that is the best level for them to absorb calcium, I will get some pics with the LEDs off tonight and get them posted and I am in a hard water area so i am using nuts designed for HW

Edited by It's 420 somewhere

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What are the temps at pot level lights on and lights off. It could be as simple as temps. Also LED's are renowned for not creating enough heat during the cold weather and rooms are too cold even at lights on

 

Owd. 

 

 

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9 minutes ago, Owderb said:

What are the temps at pot level lights on and lights off. It could be as simple as temps. Also LED's are renowned for not creating enough heat during the cold weather and rooms are too cold even at lights on

 

Owd. 

 

 

 

Hi @owderb temps at pot level are between 24c and 27c, during lights out it can drop to around 18c so i fitted a tube heater set to come on if they drop below 20c

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I'm not a hydro grower, witchcraft...lol....So I shouldn't really comment....but....I'd say cold root temps too, leading to Calcium deficiency.

It's hard to see in the LED glow, I'm wondering if there's some bleaching going on too from the intensity of the light.

Edited by Captain Bonglington

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12 hours ago, Captain Bonglington said:

I'm not a hydro grower, witchcraft...lol....So I shouldn't really comment....but....I'd say cold root temps too, leading to Calcium deficiency.

It's hard to see in the LED glow, I'm wondering if there's some bleaching going on too from the intensity of the light.

 

 

Thanks for chipping in @Captain Bonglington I will double check root temps and make sure the heater is coming on, might even raise the min temp for the heater to come on or just leave the lights on 24/7 as they are currently running a 20hrs on 4 off cycle.

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Where did the problem start buddy? lower leaves or newer leaves. I always thought calcium deficiencies showed on newer leaves first rather than the older ones. ive turned my autos on to 24hr cause 4hrs of low temps can be enough to cause lock outs in my experience, and without testing medium temps its hard to be confident the root zone isn't at least a few degrees lower especially depending on feed/water temps aswell.

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18 hours ago, Autobud said:

I don't do hydro but it looks calcium def to me, are you in a soft water area? Best to get some pics up with leds off so can see the leaf colour properly

 

As requested @Autobud here are some pics with the lights off and highlighted the areas i am concerned about. large.5c07994b988d3_LightsOff2.jpglarge.5c0799443a522_LightsOff1.jpg

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53 minutes ago, Woodie2010 said:

Where did the problem start buddy? lower leaves or newer leaves. I always thought calcium deficiencies showed on newer leaves first rather than the older ones. ive turned my autos on to 24hr cause 4hrs of low temps can be enough to cause lock outs in my experience, and without testing medium temps its hard to be confident the root zone isn't at least a few degrees lower especially depending on feed/water temps aswell.

 

Hi @Woodie2010 the spots first showed up on the lower leaves, i thought calcium so up'd the PH to try and let them absorb it easier but i am not sure if it has made a difference yet, the other 3 are looking great with no issues at all. I think i will go with a 24hr light cycle as they can handle it and it will remove any worries about root temps (i hope)

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It could be just down to an unpredictable auto if the other 3 are doing great. I always grow a few plants of the same strains and they can be inconsistent buggers at time :wallbash:. Is the problem getting any worse? 

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On 05/12/2018 at 9:09 PM, Woodie2010 said:

It could be just down to an unpredictable auto if the other 3 are doing great. I always grow a few plants of the same strains and they can be inconsistent buggers at time :wallbash:. Is the problem getting any worse? 

 

Hi @Woodie2010 I am learning they can differ greatly even when gown at the same time with the same consistent environment etc. the spots have not got worse but i have new problems now which i will be sticking up at some point today

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