Seedlings make me sad.

Discussion in 'First Time Marijuana Growers' started by jrossc, Sep 20, 2009.

  1. For the life of me I can't seem to get any of my seeds to grow any leaves. They sprout, then they grow upwards then die... I guess I just suck at understanding how wet rockwool need to be. My temps are usually high 70s to low 80s, humidity is usually around 40% (this is outside any kind of "humidity dome" i might try to use. I've tried my 26w cfls on and off, keeping them about 6 to 12 inches away. I spray the rockwool cubes several times a day with only pH adjusted water. So I'm guessing I'm either overwatering or underwatering. How do you guys keep seedlings alive in rockwool? I have a bottle of superthrive also if that will help. Im just gonna start from some bagseed... gonna start germinating them today in a paper towel while i PH adjust the rockwool. Any suggestions?
  2. Are you planning on growing hydro?

    Also, your lights need to be a little closer. CFLs can be within an inch or two of the top of the plant.
  3. you are drowning the plants bro. Rockwool holds water pretty well and spraying multiple times a day is def too much water. When plants are very young they have very little root mass so they need very little water. Wait until the rockwool starts to get lighter in weight. (when the rockwool is full of water you can def tell, it gets lighter as the water evaporates)

    GL bro :)
  4. Yes, I have a DWC bucket setup already, 150gal air pump 2 5in circular air stones, 30gal Rubbermaid container with 4 6in net pots filled with hydroton. And last time i put my cfls that close the seedlings just fell over, could have been the heat though.

    Well when i say I spray them I lightly mist the top several times a day, just getting the top damp. Is there a more methodical way to water rockwool? I think i remember reading about dipping the bottom in water... How much would I dip, and how often would I need to do this in an 80degree 40%RH environment?

    Thank you for your responses.
  5. like I said, I'd go by weight and feel of the cube. You want it to dry out a bit between waterings. Not dry like when you first buy it but dry so the majority of the water that was originally in it has evaporated. Roots need water but also need oxygen just as importently to prevent fermentation in the root zone.

    Dipping the cube from the bottom works well. If you let some air get in the cube between waterings, you can let the cube suck up as much water as it can. Spraying the tops lightly but often can be tricky cuz the bottom/cnter of the cube where the roots are could be getting too little or too much water.

    I know It sounds real confusing but once you get it down, its not even something you think twwice about :)

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