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Beginner's guide to germination with rockwool and a propogator.

Discussion in 'Absolute Beginners' started by SockPuppet, May 12, 2009.

  1. #1 SockPuppet, May 12, 2009
    Last edited by a moderator: May 12, 2009
    I am writing this guide to explain the basics of seed germination in rockwool with the help of a propogator. Soil is already pretty much covered and I'm more of a hydro lover myslef. If you can't afford a propogator or you are the DIY type like me, I will post a tutorial about how to make one soon enough. Patience my children.

    Now for the actual guide. I am using pics from the Internet, I don't have any of my own handy.

    Let us begin.

    Rockwool is alkaline, this means that it has a high pH value which will burn your seedlings if you don't prepare it properly. How do we prepare rockwool? Simple.

    Step 1:

    First of all find a container deep enough to fit your rockwool cubes.
    Fill it with distilled, filtered, spring, rain or even tap water that you have left to sit for a night or two. Then put some quarter-strength veg nute and rooting solution (according to the maker's instructions). That will ensure your plant will start in a good environment.


    Step 2:

    well, leave it alone for 15-20 mins and then measure the pH value of the mixture. If its 5.5 to 6.5 you should be ok (you need a pH value around 6).


    If your pH is not around these values, adjust it by using some pH up or pH down solutions

    Now after your pH is around 6, sink the rockwool cubes in the solution and let them be for 24-48 hours. This way the rockwool will absorb the pH 6 water, thus changing its pH value to something more friendly for your babies. Get your seedbags poppin', here's the good part.

    Step 3:

    If you just don't care about that and/or you have enough cubes, put your seeds pointy side down in the small holes of the starter cubes, press them gently so the holes close, don't push too much, we want the plants to pop out eventually but still keep it dark in there. If not, just follow the glass or paper towel method, pick the seeds that have popped with a pair of disinfected and clean tweezers and put them in the cube holes, root down.


    Step 4:
    Lay the rockwool cubes with the seeds down on your propogator tray. Cover with dome, put in sunny place or under CFL/Fluoro tube lamps (must be REALLY close to the top of the dome)



    Step 5:
    Every day or better twice a day, check the propogator, the dome should be foggy from the moisture, if not, spray the cubes with the water you kept from Step 1 and cover again. In 4-5 days you should have something that looks like that:


    Step 6:
    Almost there! Every day open the dome so fresh air comes in, spray and close it until the plants reach 1.5"-2" and roots are visible on the bottom of the cubes. Then transfer them to your soil pots or hydro system!


    Happy growing! :) Keep an eye out for more tutorials :)
  2. Thanks! Good info. + rep
  3. Great tutorial man
  4. Thanks people :D I don't see any questions though!!! :p Anyone? Something? :p
  5. Not doing hydro for quite some time, so not really. Not to mention I'll read a ton of posts before I post questions. Peace.
  6. great post man . but I have a ? . how soon after the seed pops in the cup of watrer or paper towel do you put them in the rock wool and can I use a heatmat under the rockwool or just the seedlings
  7. Seems like you're making things harder than they have to be. But as long as you're having fun, right? My method of germinating for rockwool? Drop seeds into a cup of RO or distilled water. Wait for "pop". Plant in dry rockwool. That's right, I said dry. Water with pH 5.5 RO. Done. Been doing it this way over 10 years. KISS
  8. pop meaning untill the seed cracks open or untill the root sticks out if so how far out
  9. right when the taproot is visible, you know that the seed is ok then. Of course you can use a heatmat if you wish, still the fluoros should do the trick, unless you live somewhere real cold :p
  10. Well not all rockwool is the same. Some may have had their pH preadjusted. Better safe than sorry.
  11. my grow area stays at 68-71 digrees without lights on and 45-60% humditaty . I have 2 4 foot fluoros for veging and and 2 400w hps for flowering. should I put the dome an the rockwool seedlings . thx
  12. The temp is good, since the flowering lights will raise the temp. I suggest u use one of them while vegging too, it will help raise the temp (fluoros don't) and will help the vegging too. You should use the dome, if you don't have one, do get one, they're really cheap and also you will need them for cloning (needs humidity >90%)

    with the dome over the seedlings you will ensure that the humidity will be ok for most of the day without you having to spray/water every 10 mins. and keep those fluoros right over the dome, you dont want your babies to strech and be like small green giraffes, i've seen it, not pretty man :p

    Cheers ;)
  13. thanks bro you're dig help and thanks for the thread I searched so many forums and came up nothing and yesterday I started a sticky asking for help and you probably started it at the same time . thanks again
  14. #14 dunumptanum, Nov 19, 2009
    Last edited by a moderator: Nov 19, 2009
    Hey, great tutorial!

    I have a question though - regarding Step 3.

    How wet do you keep your rockwool when you are planting the seeds? Do you leave it soaking wet, straight from the PH treatment solution? Or, do you shake it out a few times, and plant the seed into the rockwool?

    I have been following a similar method to yours, my seeds germinate fine in a glass of water, and then I plant them about 5mm deep in (PH treated) rockwool and gently brush the rockwool over the hole to cover them. Then, I have been watering the cube until I received runoff from the bottom, and placing them in a plastic dish covered in cling film.

    Unfortunately, the seedlings from my last few attempts have died at this point - I dig them out of the rockwool a week later to find that their taproot has emerged but the seedling has died, without ever emerging from the rockwool. After much reading, I am beginning to suspect that my rockwool is too wet, hence my question :)

    So, to summarise, how damp should your rockwool be, when you initially plant your germinated seed into it?

  15. Sockpuppet,

    Thanks for posting this tutorial. Answered all my questions and pics were helpful. Kicking off my first hydro grow this week. I'll be watching for more of your posts.

    Many Thanks!:hello:
  16. I have a question. What size rockwool is sufficient to grow a large plant in. Are the 3" x 3" x 3" large enough or do you need the 4" x 4" x 4" rockwool. I have been looking for an answer through old threads and cannot find it.
  17. Also to add, the rockwool would be placed into clay pellets and covered up a bit (like the Mr. Green Video) in an Ebb and Flow System
  18. BUMP. Good thread for us just getting into hydro. thanks.

    Anyone got an answer for what size rockwool you need to grow a plant in? I'm looking to start some akxlowryder 2, diesel ryder and AK-48. So does anyone have any recommendations what size rockwool to use for short-medium sized plants?

    hopefully this thread can stay alive cuz I'm sure I'll have more questions once I get my setup in the mail. just got my seeds yesterday:hello: This is my first real grow...I can't wait.
  19. One big question. When the put the ph treated rockwool with the seed in it inside the tray, should the water level be above the rockwool, below it, in the middle???
  20. Hi and many thanks :) I think the problem is that you brush the hole too tight. Try not applying any pressure on the top, just put the seed inside. I usually soak them until water starts dripping.

    Thank you :)

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