having trouble with rockwool

Discussion in 'Hydroponic Growing' started by mckillagorilla, Sep 30, 2010.

  1. so im having issues with my rockwool cubes drying out i think they are 1.5 inches. i dip them in water for 5 seconds before i put my sprouts in them. once they are in i put them in a paper bowl and set them on top of my running, compact dwc hydro system to help add humidity. they are inside a speaker i have converted into a seedling box. i have a 4 inch pan fan as an exhaust which i have stepped down to a 2 inch inlet via PVC reducer to increase the suction rate. there is a 4 inch personal fan inside blowing overtop (not on) the root cubes. this is placed about 14 inches away from the top of the sprouts. i have 2 1.5 inch passive inlets for fresh air. i am using one 23 watt 6500k compact fluorescent bulb placed about 5 inches above the sprouts.

    so i wake up in the morning and the bastards are about half dry. i lightly dip the bottom (dont wanna drown them) in water before i go to work at 9 to add a little more moisture. the lights shut off at 12 pm and turn on at 6pm. i get off work at 6 as well and usually get home around 615. when i open the box the after i get home the cubes are bone dry. this has happened twice now. i had originally put them under 2 of the twenty three watters. i have stepped down to a single bulb trying to reduce the heat in the box. even still i think the hottest it got in the box was 78 degrees which theoretically the sprouts should love.

    this is my first time and i am off to an extremely frustrating start. any input is greatly appreciated

  2. you need to get a tray and humidty dome. they are very cheap. its drying out because its getting too much dry air.
  3. or... put the rockwool on a dinner plate and put a pyrex dish over the whole thing.....

    spoon water to the plate not to the rockwool..
  4. I've found that rockwool cubes dry out fast. I usually have to dip them in water at least once a day. If you keep them in a humidity dome, they'll stay moist longer but you'll still need to usually remoisten at least once a day. When I first started using rockwool I kept nuking my seedlings because I was scared to overwater, and as result, let my cubes get wayyyyy too dry. Then I just said fuck it and kept them moist, and voila, haven't lost a seed since. It's important to keep the bottoms moist especially with seedlings to promote root growth through the bottom of the cube (and eventually into your hydro system).

    It's kind of confusing coming from soil where it's easy to overwater...just get over the fear with rockwool and be a LITTLE generous. Just don't drown them.
  5. I used a humidity dome with rockwool starter cubes for 8 clones and 7 seeds at the same time. I kept enough water in the bottom of the tray to fill up the low spots right to the top of the little channels. My theory behind this is that the rockwool will soak up the water as it needs to. the cubes stayed moist but not water logged. the way i replenished the water was to spray a mist over the plants then put the lid back on.

    i got all seeds to sprout and grow. and all clones produced roots. now they all are growing very fast in my hydro set up.

    this is how i did it and it worked great for me. i will be doing it again if i dont get my bubble cloner built first.
  6. Get a 2 litre coke bottle, leave lid on, cut off the bottom, wash clean, place over the top of your rockwool cube, thats on a dish.

    Ghetto humidity domes FTW.
  7. Humidity domes are like $2-$3...I used to do the ghetto rigs but eventually I caved and bought one.
  8. ok thank you. on a completley different subject does anyone think there is enough ventilation for them in the box i describe? ive been thinking about that a little bit...

  9. you have plenty of ventilation for right now. how tall are your plants?
  10. you want the cycle of them getting almost dry then wet again.. that makes the roots grow..if you keep them soaked u will have issues down the road,. a 1.5 cube needs to be watered daily.. Its all part of growing...

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