Brown spots? Please check my pics.

[mikep1098]

Hey guys I could use a little help. I've started noticing a few brown spots. Most of the spots are towards the center of the plant. I don't see any spots on new growth. They are most on one plant. In the first pic, it's the plant on the right. Here's what I'm working with:

Soil: Roots Organic w/dolimite lime added.
Nutes: Fox Farm Trio @ half strength.
Light: 400w hps
Temps: 80-82f day, 75 night. 35-40% humidity
Ph: Water 6.4-6.6 Runoff: 6.6-6.8

Thanks for any help!

 

[neved]

I think u shoud water with lower ph like 5.80 ....and if u have ppm meter u can up yr nut more with that light green leafs ....

 

[mikep1098]

You think I should use 5.8ph in soil?

 

[sweetcheekz]

I'm no expert, from everything I've read soil wants 6.5-6.9 PH.

I'd get a 2nd opinion before following neved's advice (no offense neved)

 

[MrGhettoGrower]

In dirt the runoff test isn't very accurate usually the ph is really lower the ppm is higher than it really is. Fox Farm even says don't go by the runoff test they say use the slurry test or whatever. I don't even believe in the slurry test much either any more. But here's the link to fox farm it's the 6th paragraph down under helpful hints. http://blog.foxfarmfertilizer.com/soils/


Once I'm got'em going in flowering it nothing but full doses of nutes every other watering/feedings. And I try that adding lime before using and I'll never do it again. Ph everything 6.5 or a little higher but not over 7.0 for soil~
The plants kind of big for your pots what size are the pots how tall are the plants?

 

[mikep1098]

Thanks for the reply. I think my PH is okay. I've really tried to stay on top of that. I was thinking my PH was too high, if anything. I'm using half strength nutes every watering. I was starting to have some N def only so I started feeding every watering. From what I've read, it should be fine to use half strength every watering, instead of full strength every other time.

The pots look small in the pic, but I agree they could be bigger. They are in 2 gallon pots. They are autoflowers, about 5 weeks old now. 28" tall.

 

[nog]

could be to do with the heat

 

[obijohn]

I have some spotting like that as well. I balance the PH of everything I put into the pots (FFOF also) They may need a flush, but I'm going to wait another week or 2 because they still have a few weeks until they are ready

 

[mikep1098]

could be to do with the heat

I don't have heat problems.

 

[mikep1098]

More spots are starting to appear! A couple of the spots are now appearing on newer growth. Its still only on 1 of 3 plants. I just watered/fed them a few minutes ago.
Feed water: 6.5ph
Runoff water: 6.6ph

Any thoughts?

 

[matticus408]

Do you have any kind of reflective material around or above your plants? If so, non flat reflective surfaces can focus light and make burn marks similar to what you have. just a thought.

 

[Tennis1]

Looks like some sort of disease.

 

[Tennis1]

Then again maybe some kind of acidic liquid dripped on them. Do you use anything to lower your ph near by?

 

[mikep1098]

Anybody? I'm seeing a few more spots. I am 100% confident that nothing was spilled on the leaves, no way. And no it isn't hot spots from the light.

Thankfully, it is still only happening to one plant. All three plants are the same strain with same feeding regimen.

Yesterday: PH feed water: 6.4 Runoff: 6.6

My pH seems to be great, right? I'm giving 1/2 strength nutes(FF). Adding cal/mag(using RO).

My temps are still good. Day 79-81. Night 74-76. Humidity 40%

I'm really stumped about this.

 

[Tennis1]

Is it corrosion chunks falling from the light housing? That might sound crazy, but it happened to me once.

 

[SirPsycho]

i can honestly say that i don't know the exact problem, but it's got to do with what's in the grow medium(soil); could be some kind of deficiency, nute lock-up, etc. Just do a good flush man, and you'll be alright, nuff said.

 

[mikep1098]

I appreciate all the guesses.

Hasn't anyone seen this problem before? C'mon guys, someone's seen this before, I'm sure!!!

THANKS!

 

[303]

Maybe something to do with your water, have you test the ppm of your tap water? Are these all the same strains or different?

 

[mikep1098]

Maybe something to do with your water, have you test the ppm of your tap water? Are these all the same strains or different?

3 plants, all the same strain. Only one plant is effected with these spots. I'm using RO water. 0ppm.