Brown spotting on leaves...stumped.

[low_and_slow]

Soil Grows - Peat Based

First time grower

Your Equipment:
.1) Type and wattage of lights. Blackstar 240 LED
.2) Distance from tops? 25"
.3) Reflector type? LED housing
.4) Is there a consistent fresh air supply? Yes, door is always open
.5) Do you have an exhaust fan and a circulation fan? Circ fan
.6) What are the bulb wattages, kelvin ratings, and schedule? 18/6

Your medium:
.7) Specific brand and type of soil, (coco, peat based soilless...) and anything you've added to it. LW + Perlite + Lime to PH balance
.8) Size of container. 18oz Party cups, PJEMs are tiered into 4 gal pots (did that this morning)

Your nutrients and water:
.9) Source of water. (tap or filtered) What's it's ph? tap, left to sit out overnight in an open container. PH to just below 7
10) Method of checking water ph. Chemical shaker kit
11) Method of adjusting water ph. GH up/down + lime in the soil
12) Specific brand and N-P-K ratio for each bottle. List dosages (quantity per gallon) and current feeding schedule. No nutes yet
13) How often are you watering between feedings, and how much per watering? 4-6oz of water, twice a week
14) Any additives or tea's? (Superthrive, CalMag, molasses, Mother's Earth...) None
15) Are your ph levels stable, or do they fluctuate? Mostly stable, I've only checked once or twice and it was g2g before I put the seeds to soil.
16) What is your ingoing water's ph? ...your runoff ph? just below 7 going in, looks about the same coming out.
17) Do you foliar feed? If so, with what, how often, and at what time do you spray? Gave them a spritz with PH'ed water once, but that was after they already had developed some spots.

Your growroom:
18) Indoors or outdoors? Indoors
19) What size of closet, room or hut? Closet, 46"x22"x72"
20) What are the temps and humidity levels while lights are on? ...With lights off? Mid-high 70's, humidity unk.
21) Have you seen signs of insects in the growroom? A couple of little no seeums, but there's nothing noticeable on the plants.

Your strain:
22) What strain are you growing? (PJEMs and Iranian Autoflower, not sure on genetics)
23) Is this an photoperiod strain? (Pjem is auto, IAF is early photo)
24) How old is the plant? (PJems are 1 week, IAF are almost 3 weeks)
25) In what life-cycle is it? Vegetative, pre-flowering, flowering, rippening? (Veg)
26) From seeds or clones? (Seed)

What do you guys think? The Pjems are just starting to show traces of little spots on their first set of true leaves. The spots start as little lightly colored translucent patches that then turn brown and crispy over time. I'm stumped.

 

[Hugo]

Hi low,

Thanks for filling the form, most appreciated and + max rep for that.

I'm also a bit stumped with this one. My first guess would be Calcium, but since you've added limestone to the soil that pretty much excludes that possibility. It could also be Magnesium or Phosphorous deficiency, even though very unlikely due to being so early in the life cycle. Mg only shows signs after 4 weeks, and you seem to have been getting them since week 1...

Assuming you have the pH controlled (those colour charts are ok but they can be misleading on the run-off because of the change in water colour), those are my best diagnosis.

Can you take a picture of the whole plant? Is there some leaf where this is early staging? Take a pic of that also please. I assume correctly that this started to appear in the lower parts of the plant first?

I'm waiting for your reply and for somebody else tuning in to help.

 

[Hugo]

I'm not sure about those additions to the Light Warrior. It is already fast draining so perlite seems unnecessary. I don't know about the lime.

advises growers to start feeding within 5 days of planting and germination with this soil. Even if we are talking autos in here, they'll need to have some food to grow well, so starting your doses on the low side is allways good. That soil is a light mix (a good one it seems), so you have to start feeding early like they state. Your IAF is definetely starving and you should start feeding her asap. What nutes do you have?


A side note:
A friend as called to my attention that perhaps your lime is not suited for agriculture? What lime are you using.

 

[low_and_slow]

I'm using dolomite lime, as recommended by the folks at the garden center, for horticultural use. As far as the LW being fast draining, you're probably spot on there...the added perlite is probably too much drainage, maybe necessitating extra waterings. As far as the plant showing these spots due to lack of nutrients...hmm...maybe I could try giving her a 1/4 dose of seedling nutes (I'm using the GenHydro organic "Go-Box"). My fear is that the problem might get worse if I give her some food too early...the JEMs are showing the spotting now as well, and they're just a week old today, no nutes, nice light seed starter mix. I'll get some pics of the whole plant here in a minute and post back.

 

[low_and_slow]

http://generalhydroponics.com/site/index.php/products/general_organics/go_box/

^nutes^

 

[Gandolph420]

Just a suggestion, maybe lower your ph down to the low 6's, 6.5+ is starting to get a little high in my opinion. I would also start a light feeding regiment, and underwatering would also cause a really "drooping" plant from my experience, so I wouldnt water too much.

Goodluck!

Good Karma sent your way...

 

[Gandolph420]

Also, I would invest in a digital ph meter, I dont know how accurate those Shaker kits are.

 

[beavergoods]

A GOOD ph meter I wouldnt spend less than $100 unless youre getting a sick deal on something you know has a higher value.

BeaverG

 

[riz]

You might Have Leaf Spot Fungus. I cured it before with Essence http://www.plant-magic.co.uk/products/essence.html

But because it's just the seed leaves i wouldn't worry about it until you see it develop further up. How old are the plants?

 

[low_and_slow]

Okay, this is the "worse" of the two PJEMs. I don't have any full pics of that iranians, but basically this is what it starts to look like right at the onset. This plant is 7 days old since germing.