Yellowing Leaves, Brown Tips, Random Spots

Discussion in 'Sick Plants and Problems' started by ralph wiggum, Mar 10, 2012.

  1. Sorry, I've been trying to research an answer to this on my own for a week; meanwhile the problem has continued to get worse. I really need some knowledgeable advice on how to help my plant ASAP.

    Indoors or outdoors? Indoor single plant micro grow
    What type of medium; soil or hydro? Soil
    What brand and type of soil? MiracleGro Moisture Control (I know, I know... I think this is where lots of the issues started)
    What strain? Bag Seed
    How old are the plants? 4 weeks from seedling
    What type of lights and how many watts? 4x 23 watt 6500k CFLs above, 4x 24watt 2ft T5HO tubes on the sides
    How far from the lights? 4 inches
    What is your watering frequency and source of water? Every other day with tap water that has sat for 24 hours before being poured into a reservoir aerated with an aquarium pump and air stone
    What, how much and when was it fed? NPK? None, aside from the soil
    What is the medium/runoff pH and PPM if in hydro? Don't have pH meter yet
    What are the temps and humidity in the room? 50% RH, average about 90F prior to adding an intake fan, about 86F after
    What size pots? 3 Gallon smart pot, sitting in 5 Gallon smartpot
    Any bugs? Look real close. A few carpet beetles, some gnats.
    Any other pertinent info?

    Complete history:
    Started seed in Jiffy disc. Planted to a 3 gallon dirt bag/smart pot. Used MiracleGro Moisture control (because I didn't want to think about it... yeah right! :().

    I noticed signs of distress after a couple weeks of planting. I attributed this to the soil, so I flushed pretty heavily for about 5 days.

    At the end of flushing, I noticed roots poking through the bottom of the 3 gallon container, so I simply put the 3 gallon smart pot into a 5 gallon smart pot.

    I think I tried to get too cute with it... in the 5 gallon smart pot, I simply filled with perlite. I also put a tube in the bottom of the pot attached to a fish pump, so air is constantly being pushed in there. (Too much in terms of "airy soil"? haha)

    At the same time, I moved it from sitting openly in a closet into its intended home, a 18x18x36 grow cube. Temperature was far higher in there than ambient temps in the closet. As I mentioned, it was up around 90, now in the mid 80s. Probably going to add more computer fans I guess.

    Do I need to flush more? Did my previous flush remove too much nutrients from the soil? Heat stress? Nutrient deficiency (from flush followed by no feeding)?

    Please help.

    Also, in one of the attached pics, you can see where the first "true leaves" have withered away--not sure if that's to be expected or another symptom.

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  2. #2 ralph wiggum, Mar 15, 2012
    Last edited by a moderator: Mar 15, 2012

    Plant continues to deteriorate.

    The computer fans on the box weren't cutting it, so i placed a box fan atop the box and set it on low. Not a permanent solution, but basically the only option for now. Temps are now down to 79-82F and have been for several days now.

    Will likely pick up a exhaust fan/carbon scrubber combo soon and before going to flower. Using the equation from the Ventilation FAQ, I need to move ~70cfm to properly cool the box. The one I'm looking at over on HTG is ~170, and they say prolly ~150cfm when pulling through the scrubber.

    Picked up a Milwaukee ph600 (just to have something better than my homebrew pH strips). Calibrated with pH 7.0 solution. Following are some data points I collected:

    8.7 - pH of my water directly from the tap (listing just for reference purposes).
    7.7 - pH of water used to water plants (from aeration reservoir).
    7.0 - pH of runoff from soil (I did water yesterday as well, if that makes a difference)
    7.1 - pH of soil sample that sat in distilled water for 20mins

    So certainly it seems like I have a pH issue. If someone could tell me how to fix it, that would be great.

    Other developments:

    - I've disconnected the air tube that goes into the perlite in the 5 gal pot.
    - Roots are beginning to poke through the 5 gal pot now as well.
    - Nutes are on the way, but won't arrive till Tuesday. I think at 5 weeks now (and after flushing the "Miracle" Grow), the plant is starving. Could be multiple nutrient deficiencies I think.
    - The leaves are very brittle in general, and the parts that are brown/tan break very easily. Thoughts?

    Outstanding questions:

    - Any advice on how to get the pH down?
    - Should I mix superthrive (which I already have) into my next watering since it will still be a few more days till my nutes arrive?
    - Any other advice about how to get this plant healthy again? Foiliar fertilizing?

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  3. How often do you water? pH should be closer to 6 than 7. any hydro store will sell a 'pH down' solution. i think your girl could use some nitrogen.. also defoliating the lower most portion of the plant isn't going to hurt, the leaves that are damaged from stress are likely only sustaining rather than thriving or growing and potentially adding to a net loss for the plant. temperature should be in the mid 70's not mid 80's. do you not have a hydro store or horticulture retailer near you?
  4. #4 ralph wiggum, Mar 16, 2012
    Last edited by a moderator: Mar 16, 2012
    Thanks for responding ptown!

    I'm watering every 2-3 days.

    There are a few gardening centers nearby that I probably ought to check out. For better or worse, I've been getting a lot of supplies off Amazon. Ordered some "Atlas Scientific" pH down after reading your post. I've been trying out their Prime program, so the package should be here tomorrow when I get home from work... quicker than me being able to get to a gardening shop. And $4 for overnight shipping? :cool: (Although it does suck when something isn't eligible and I'm stuck waiting.)

    I picked up some apple cider vinegar at the grocery store tonight... thinking about diluting it and doing an emergency watering just to try to begin correcting the pH until the proper stuff gets here tomorrow. Some threads I've read say that vinegar is a temporary solution for soil pH adjustments, and it may last no longer than a few hours... that's why I was thinking of jumping the gun and starting with that now. Or should I just be patient?

    One follow up question: you're saying I should remove the leaves that are really messed up so the plant doesn't waste energy/time/nutrients trying to help them?
  5. ^ Dead leaves are not a drain on the plant. Dead leaves are simply dead; theres a layer of cells separating live tissue from not. There is no maintenance and no exchange. Any green portions of the leaf will photosynthesize and add a net gain to the plant; there is never a net loss from any damaged leaf - plants don't work that way. Leaves are simply dead because the cells within them were either used for salt storage, or nutrient withdrawal.

    HOWEVER - damaged leaves can and do block light from other photosynthesizing surfaces. If a leaf has been overly damaged or burned and covers underlying leaves, its good to remove it. If there are no underlying leaves, leave it - your plant is using the leaf for nutrients. Every time you remove a damaged leaf the plant has to hesitate for a moment, take stock of its situation, and get a new salt dump / nutrient reservoir - when you remove damaged leaves, the plant searches for a new leaf to damage.
  6. The plant could be spending more of its energy and nutrients building the top portions that are going to put on the biggest flowers.. the underlying leaves and branches are not doing as much as they could because a smaller percent of the light is filtering through for them to utilize in photosynthesis. in my experience i've always got better yields from removing the lower portion of the plant that isn't receiving very much light, as well as thinning out damaged leaves. my plants are happy, and i thin them like crazy.
    there is very little plant biomass under what you see right there, because that is where you will maximize your photosynthetic potential. to each his own though, experiment and you'll find out what works for yourself
  7. ^ Little difference in your set-up where they are all healthy, and his plant. After everything is fixed, I would agree with a trim - the plant wont actively damage any more leaves.

    I completely agree with removing anything under the top canopy in vege and approaching flower (in terms of growing shoots) but until then leaf matter is better off as nute sinks or salt dumps - in less than ideal conditions, such as what the OP is experiencing.

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