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Leaf discoloration/death

Discussion in 'Plant Problems' started by Ziggilus, Jun 12, 2010.

  1. Ziggilus

    Ziggilus Registered

    I think I have a deficiency of some sort in my plant. Four days ago I noticed a slight discoloration in some of the lower sets of leaves. I figured it had probably eaten through the nutrients already in the soil, so I decided to give my plants it's first feeding.

    The discoloration has now begun moving up the plant, and the lowest sets of leaves are dead.

    I've read through descriptions of nutrient deficiencies but most of them are pretty ambiguous and I'm having trouble pinning down what is the likely culprit. Nute burn seems pretty unlikely, since the problem started suddenly a couple of days ago, before I gave the plant anything. So basically my question is: does anyone have any idea what causes this sort of discoloration?

    1(2).jpg
    2(2).jpg
    4.jpg

    Thanks.
     
  2. Rusty Trichome

    Rusty Trichome Registered+

    Could be a couple of things. Copy-n-paste the proper troubleshooting form here, and fill it out as best you can. The more accurate the info you provide is, the more accurate the diagnosis and treatment plan. Takes a few minutes, but worth the effort. :thumbsup:

    (the link the the troubleshooting forms is in my signature. Use the one for soil grows)
     
  3. Ziggilus

    Ziggilus Registered

    What is your experience level? first timer

    Your Equipment:
    .1) Type and wattage of lights. 152W of CFLs
    .2) Distance from tops? 2-4 in.
    .3) Reflector type? None
    .4) Is there a consistent fresh air supply? Yes
    .5) Do you have an exhaust fan and a circulation fan? Exhaust only. (Inside a rubbermaid container, so the exhaust essentially circulates as well.)
    .6) What are the bulb wattages, kelvin ratings, and schedule? 6 x 26W, 6500K, 24/0

    Your medium:
    .7) Specific brand and type of soil, (coco, peat based soilless...) and anything you've added to it. Miracle Grow Potting Mix
    .8) Size of container. It's about 9 inches across and 7 inches tall, not positive about its volume.
    .9) Did you use peat pucks (or similar) to root clones or germinate seedlings? No

    Your nutrients and water:
    10) Source of water? (tap, bottled or filtered) What's it's ph before adjusting? Bottled distilled water from Hy-Vee (I can only assume its 7)
    11) Method of checking water ph. None :(
    12) Method of adjusting water ph. None
    13) Specific brand and N-P-K ratio for each bottle. List dosages (quantity per gallon) and current feeding schedule. Schultz 32-10-10, 1/4 tsp per gallon. Fed for the first time 4 days ago.
    14) How often are you watering between feedings, and how much per watering? Lately I have been watering every 2-3 days.
    15) Any additives or tea's? No
    16) Are your ph levels stable, or do they fluctuate? Unknown :(
    17) What is your ingoing water's ph? ...your runoff ph? Unknown
    18) Do you foliar feed? If so, with what, how often, and at what time do you spray? No

    Your growroom:
    19) Indoors or outdoors? Indoors
    20) What size of closet, room or hut? The rubbermaid tub is about 2 ft long, 1 ft wide and 1.5ft tall.
    21) What are the temps and humidity levels while lights are on? ...With lights off? I don't have a temperature/barometer, but the exhaust air feels only slightly warmer than the ambient room temperature (about 70 degrees).
    22) Have you seen signs of insects in the growroom? No

    Your strain:
    23) What strain are you growing? (Indica dominate or Sativa dom?) Unsure, this is a bagseed grow.
    24) From seeds or clones? Seeds
    25) Is this an autoflower strain? Not as far as I know. (I'm assuming not)


    I definitely need some pH measuring supplies.
     
  4. Ziggilus

    Ziggilus Registered

    I got a pH test kit. The distilled water seems to be around 6.4. I put a sample of soil in a coffee filter and poured some water through it and the pH dropped down to around 6.0 =/ so maybe it is a lockout problem. I'll properly test the runoff pH when I get up tomorrow.

    Whatever the problem is, it's getting worse pretty fast. Today the leaf in the first picture is completely shriveled and dead, and the leaves in the second and third picture are much more discolored. I'm afraid the whole plant will be dead within a week if I don't figure out what's wrong. If the runoff pH is low I'll probably end up doing a flush.

    My tap water's pH is about 7.5, so I mixed that with the distilled to get a gallon of 6.6 water if I do need to flush, is this a good pH to aim for? Also, if I do flush, should I give it a light feeding immediately after? Or wait a day or two?

    Thanks again.
     
  5. Rusty Trichome

    Rusty Trichome Registered+

    You already know you'll need a method to check ph. Might even need something to adjust ph. But why aren't you using tapwater? (just curious)
    It's cheaper to adjust your tapwater, than to keep buying inconsistent bottled water.

    Is the Schultz in liquid or powder form, or is it a time-release formula? (time release pellets)
    How long have the plants been in the MG soil? It takes a month or so before the nutrients in the MG soil deplete enough to start 1/4 or 1/2 doses of your nutrients.
    What dilution rate does the Schultz say to use, and how often does it say to use it? (1 tsp per gallon per week, for example) Way high N-P-K ratio. (see below)

    Are you letting to soil dry-out pretty good between waterings? (and feedings)

    You can not properly test runoff ph with one of those ph test kits with color-coded results. Any tinting of the tested liquid will skew the color-coded results. You might not even be in the ballpark for your runoff ph number. Until you can get a ph pen, don't concern yourself with an inaccurate test.
    Same goes for ingoing water that has colored nutrients added. The tinting of the water skews results.
    MG is pre-buffered and should have plenty of buffers to last aboout 2 months before fading. It's buffered to pretty much neutral ph. (6.5 to 6.8, if memory serves me correctly)

    My guess is overdose, and possibly ph swings. But more likely it's the nutrients. I'd flush well, and no nutrients till at least the next scheduled feeding day. Your schultz is very strong, and I'd consider lowering your dilution rate to 1/4 of recommended dose.
    The ph of bottled water isn't always consistent. My water ph is high, so I use phDown by General Hydroponics. It's a weak phosphoric acid solution that works well. 1/4 tsp lowers my well water ph from 7.9ish to 6.8ish. (a bottle lasts a while)
     
    Last edited: Jun 13, 2010
  6. Ziggilus

    Ziggilus Registered

    Thanks for the help Rusty, sorry I didn't reply sooner I've been busy with my job hunt the past few days.

    I only have the one plant and I'm really just getting my feet wet with this grow, so I'll have more experience for a more serious grow later on. Distilled water is only $0.92/gal at Hy-Vee, so I can get enough it to last the entire life of my plant for cheaper than a bottle of pH down.

    The Schultz is in powder form, and my plant has been in the MG soil for 3 weeks now. So I guess I probably didn't need to give them any food, I only did because I noticed some yellowing starting on the bottom leaves.

    Anyway, I flushed 2 days ago with 2 gallons of water. The discoloration has stopped moving up the plant, the leaves stopped drooping and the plant has begun growing with renewed vigor =)

    The plant is now about 10 inches tall, and I was planning on starting to flower when it was a foot tall. I haven't fed it at all apart from the nutrients I just flushed out. Would it be unreasonable to start flowering in a week or so, and just start giving it flowering nutrients?

    Thanks again for all your help!
     

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