Auto Seedlings Turning Brown And Drooping, Hydroponic

Discussion in 'Sick Plants and Problems' started by Charlie Rogers, Jun 5, 2013.

  1. Hey everyone,

    This is my first grow and having next to no experience with growing, I'd hope to get some advice on my current situation from some seasoned growers.

    My setup is a homemade ebb and flow. I have a 20 gallon reservoir, going to a tray with 11 6" net pots. I'm growing all auto flowering strains. I'm also using a 400w MH light at about 18" away from seedlings.

    My strains:
    Auto northern lights
    Auto Red poison
    Auto Berry Ryder
    Auto purple kush

    The problem I'm having is my plants starting drooping a day ago and now they begun to turn yellow/brown. I germinated the seeds almost 4 weeks ago in rw cubes and definitely feel they've been stunted because of the underlying problem I'm experiencing. I germed them under a cfl on a 24/0 light schedule for the first week then put them in the hydro setup under the hps with a 18/6 lighting schedule. I foolishly added very low strength nutes (general hydroponics brand) to the hydro reservoir, maybe 1/8 strength or so, and don't know if my plants have mute burn or maybe some defeciency.

    As for temps I'm reaching close to 90 F when the lights been on but now have a fan blowing across light and plants. Temps reach 65 when lights off.

    I just today refilled the reservoir with new water after cleaning it out. I only put in fresh water phed to a little under 6. I'm hoping this will help the plants since I've read autos do not like nutes until flowering.

    Any help would be greatly appreciated!
    And thanks in advance for the help!

    Attached Files:

  2. After a full light cycle and dark cycle with the plain un-nuted water, the plants seem to still be in their current state. I thought maybe atleast the drooping or downward curling leaves would lessen incase it was nute burn.
    I might add that when I added the nutrients to the first reservoir fill, I only used the floramicro and floragro of the three part system. After reading the labels, I noticed that the third part, the florabloom contains a much larger amount of magnesium then the other two parts (5% compared to .5%) The directions for the system also say to use all three parts in equal parts for seedlings (I know autoflowers dont usually follow this rule though). 
    Do you guys think that maybe since I didnt use the third part, the water was lacking in magnesium thus causing these symptoms? 
  3. #3 Charlie Rogers, Jun 6, 2013
    Last edited by a moderator: Jun 6, 2013
    Hey guys, im really struggling here and would appreciate any help at all. I feel like I may have left out little bits of info for my setup and whatnot. So ill try to fill in anything I may have forgotten.
    I germinated the plants in 1.5" rockwool cubes exactly 4 weeks ago from today. I put them under a 45W cfl on 24/7 for the first 12 days and occasionally misted them and wet the cubes with 6 pH water with a few drops of veg nutes in it. It was on day 13 that I moved the cubes into 6" net pots filled with hydroton. The cube I covered with a small layer of hydroton.
    The plants seemed to be very slowly growing since until about a week ago that I noticed a few leaves had brown barely noticeable spots. Now they have turned into the above pictures. I flood my tray 3-4 times a days for 15 minutes. I used tap water to fill my reservoir which contains air stones running 24/7. The water is very soft, basically 0 ppm.
    Like I said above, I changed out the reservoir with plain tap water, which I adjusted to a pH of 6, a few days ago. The water in before had maybe 1/8 strength floragro and 1/8 floramicro.
    Im growing in a closet which is why also my temps are peaking around 90 F.  There is an AC installed in the room, and I do have an exhaust fan blowing air through the ceiling and out of the room.
    At this point I'm really stumped at what exactly it could be. The plants are not showing any signs of getting better and Im torn between so many possible problems it could be.
    I thought maybe nutrient burn, then overwatering, and then a Magnesium def, but the stunted growth also made me think nitrogen or phosphorus. 
    If anyone can offer any input, id greatly appreciate it. I dont want these plants to perish.
    Also attached is a more recent picture of a plant with browning leaves and curling.

    Attached Files:

    Thank you for the response and link!
    I took a look at that site but nothing I read really sounded familiar with whats going on with my plants.
    After having just plain water in my resevoir for the past 3 days, the plants are not showing any signs of improvement which makes me believe that maybe I need to add some mild nutes to the water.
    What do you think?
  5. Congratulations for getting so far on your first effort, shit you have done and learn't much too, you would have got very little from books, that five minute in your closet would have taught you, I do hope you have all the tools, Ec probe and Ph thingy and perhaps some pool strips in case things go bad.
    Like humans plants have a limited on board food, once hatched, though plants (Mj) can go for about 1-2 weeks before requiring an external food source, so lets slow down your feeding regime, to 20% of your current issuance ..never be afraid to flush the system, many growers do it 1x time per month regardless
    Once you see the green of the leaves return wait 2-3 days then re add nute sol, to your system but only 20% of your previous feeds, do it slowly so you get a chance to learn what your babies are 
    In future don't mix strains try to stick to one strain per batch so you again learn more about each strain, and there issues..
    what bothers me is your tray only waters 3-4 times a day, when I used this system...back in the '80s I washed the roots every 120 minutes, and a friend still insists that one should flood every hour, in order to stop roots drying out 
    Good Luck and report back in about 2 weeks 
  6. I'd follow the advice from vostock, i don't have a great deal of experience with hydroponics set-ups. I prefer soil as my medium, just a personal preference. I would agree you need to fill the trays more than 3-4 times a day though and go easy on nutes, too much early in the growth stage will cause plants in any medium issues. 
  7. I'm happy to say that I figured out my issues with my plants. It was actually completely the opposite of what I thought. I wasn't giving the plants enough nutes! The lack of nitrogen, phosphorus and potassium were causing the stunting, yellowing leaves and curling. I'm up to about 75 percent what GH calls "aggressive vegging" and floodin every 2 hours. The plants are loving it! I guess auto flowers maybe aren't ridiculously sensitive to nutes as I thought.

    Thanks for all the advice though!

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