Rockwool turning green..

Discussion in 'Hydroponic Growing' started by Eu4ik, Oct 4, 2010.

  1. Hey all,

    I am a few weeks into my grow, and in one container my rock wool is turning from brown to green. WTF is this?? Is it normal, has it happened to any of you. I'm worried if it is mold.

  2. algae...

    add hygrozyme to your feed, it will go away.
  3. Is algae necessarily a bad thing?
  4. It will eat up your nutes - which I assume you have other plans for.
    Also algae will gum up the works in general in a hydro system.
    I make up a 1% solution of Hydrogen Peroxide and squirt it right on the cube.
    A little goes a long way.
    I see brighter and whiter cubs in one application and in 24 hrs.
    Note: Too hot a H2O2 solution will make your roots very unhappy and you want to keep it off your leaves as well.
  5. cover the tops of the cubes with something that blocks the light. It will go away after that.
  6. COver the top huh? That seems like an easy fix.
  7. Like Pd Bagger told you ,cover the tops.I had the same problem before.I Covered them up and the problem was solved.
  8. Cool, I will do this. Is a hydro shop gonna have a cover for it?
  9. just get creative.... I cut out squares from my mylar and covered them... Also doubles as a light reflector to shoot back up! :D
  10. yeah like ^ said, get creative. Since I use black visqueen for other things, I had some lying around. You just need to cover the top, much like the rockwool cubes have them covering the other 4 sides (well, the grodan ones I get do).
  11. There is a problem with "shooting the light back up" as you describe.

    It's called "Competitive Growth". What it means is that when a plant "sees" light on the underside of it's leaves, it "sees" it as reflected light from a competing plant near it. In nature, the resulting action the plant takes is to increase it's Inter-Nodal length and to grow as tall as possible as fast as possible.

    With marijuana, that's not a good thing. It makes lanky, stretched out plants with less flowering points. Nice tight Inter-Nodal length and stocky, bushy plants are what we're all after. Lots and lots of budding sites.

    If side lighting is used, it's best to use it from an angle where the light strikes the top of the leaves, not the bottom.
  12. Algae is not a good thing. Like the previous poster said, it uses nutrients. It also will cause your pH to fluctuate.

    The best preventative is to cover your media with black plastic or with additional hydroton or whatever media you use.

    It takes water, nutrients and light to grow algae. The only reasonable one of the three to take away is the light. Just block it from hitting the media or rockwool.

    I aways bury my rockwool at least 2" below the surface of my media.
  13. The worst thing algae can do is encourage pests like fungus gnats to start feeding off it and then onto your roots. I always cover the rockwool in my pots with about an inch of clay balls and never have the problem. Good luck with it.
  14. I like that idea, I tried wrapping them up in black plastic bags. Not 100% light proof, but way better than before. I also picked out the algea on top, and added a new layer of rockwool. I really want to get some clay balls, but i just don't have the cash. Today my 150w HPS came in the mail! So i am pretty happy.

    Attached Files:

  15. HAH! I'm a step ahead of all you guys! My rockwool is green to start!
  16. well claude, if it looks like this kinda green, you will also be one step ahead of us watching your plants die. :)

  17. I have a deal going with the algae: they don't show up here and I don't go swimming at their place.
  18. Bagger, mine was just like that, but my entire medium is rockwool, and it was no where near that close to my stem. I picked out everything and haven't checked under the bag yet.

    LOL Claude, you really need to keep an eye out for it if you aren't wrapped up. Practice safe growing, and bag up your medium. You might get some nasty things growing down there.
    • Like Like x 1
  19. I had this issue, and now have to get rid of the fungus gnats. I got some of those 4" rockwool covers to keep the light from the rockwool. I also got some of these sticky bug things to get rid of the gnats. Hope you don't get these!
  20. Gnats would be horrible, I took care of the situation pretty quickly, so I don't believe any will show up. Also I have a cat that would notify me of any pests i.e. f-ing with my set-up.

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