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How do YOU get clones to root in rockwool ?

Discussion in 'Basic Growing Information' started by marski420, Jun 21, 2012.

  1. I just tried my second batch and its looking like no luck again! Its been 11 days and no signs of roots. Im mostly just wondering what some of you do to get good ratios in rockwool? I keep my grows simple, lucas formula with a couple added boosts in flower. If you think your method is top notch tell me step by step so I can give it a whirl. I think I'm having such poor luck because I'm not using a heat mat and my temps flux from 70-80.

    I have also heard by many people aero cloners are the shit, easy and roots in a very short time. How inexpensive is it to make one yourself? Thanks farmers.
    dan1989 likes this.


    F- aero cloners. Rockwool and a very little a and b, a little roots excell (or not) and time is all you need.

    Heat mat will speed it up a bit but is not necessary.

    I use GH micro and boom in very small amounts with R/O water. Bring it to about 250-350 ppm, ph of 5.8-6.1.

    Prepare cubes by placing in a very light nutrient solution and roots excell (or not) and PH prep water to 4.0. Soak for 12 hours. Flush out cubes by holding lightly and do a modified throwing motion over the sink stopping your arm before it hits the sink. I do this 8 or so times per cube until 80% of the water is forced out of the cube.

    I then PH adjust the water they were soaking in to 6.0 or so (the water will be very close to that PH already as the cubes alkalinity will naturally raise your presoak water's PH). I then use a siringe to apply a small amout of the PH'd water into each cube.

    I then take each cut and place stright into cup of water with PH'd water for 10 seconds before placing in cube.

    I use and 18/6 light schedule with florecent T5 lights. I get roots on 100% of my cuts using this method. Some take 6 days. Most take 10 days. Tough rooting strains have taken 3 weeks. But all eventually get roots.

    Do not let cubes get too wet before roots appear. If you do they won't make roots. They don't drink much until they do get roots. So, you should only have to apply water on like the fifth or sixth day. But not too much! Use the weight of the cubes to determine whether or not they need water.
    MCC420, Samoan, ShroomKing and 3 others like this.
  3. waayne


    marski420 generally if you're having problems rooting in Rockwool it's due to the Rockwool staying too moist.....

    Let those cubes dry down some,but not bone dry.....those cuts need oxygen just as much as moisture to root.....

    Good Luck!
    dan1989, Samoan, MSH and 3 others like this.
  4. Love the farm.. great people with quick replys.. thank you very much!
    dan1989, Samoan, embaks and 1 other person like this.
  5. I'm new to rockwool cloning too... 2 batches with nearly perfect success tho. I never shook the excess water out but I like that idea. My cubes stayed damp from the soaking almost until they rooted... Maybe spraying down once before roots were visable. I just kept the dome super humid. I consider rockwool easier to clone with then my aero cloner...
    Samoan and ShroomKing like this.
  6. A couple things, I use the micro and bloom too but dont have a PPM meter. How much micro per gallon and how much bloom roughly? Im also a little confused about how you said to bring it to a ph of 5.8-6.1 but then say to soak the cubes in 4.0 light nutrient solution, is this a different solution or something and if so why am I making that batch of 5.8? If its the same solution wouldnt I just try and get it to 4.0 instead of making it 5.8-6.1? I dunno maybe Im reading that part wrong or something lol. One other thing is are you using a humidity dome and if so how often are you leaving the lid closed and how often do you give them air? Thanks a lot for your time bro.
  7. waayne


    I use 1/4 tsp of Micro, Grow, and Bloom mixed in a gallon of Distilled water
    the PH will be about 5.8-5.9 >>> the ppm will be about 250-300
    I soak cubes 12-24 hours in distilled H20 adjusted to a PH of 3.5-4.0 then drain them,and give them a little of the nutrient solution
    and drain off the excess, then I'm ready to cut clones
    From the time I cut the clone until I stick it in the cube is less than 2 seconds so as to avoid embolisms
    My clones never droop with this technique
    I don't use gels or powders either,they work, I just don't see the need for them personally....

    Sometimes I use a dome, sometimes I don't,It depends on ambient humidity levels and my mood
    If I don't use a dome, it usually takes 5-7 more days for them to root
    If you use a dome always remove it a few times a day for a couple of minutes so the clones get some fresh air,and make sure the dome has vents
    Don't over do it with too much humidity>>too much humidity can cause them to to get pale and yellow......and inhibits rooting

    I use T5's running constantly
    They get about 200-250 ft. candles while they're rooting then once I see roots I start to increase light intensity gradually

    I ALWAYS use a agricultural heat mat set to 77 degrees

    OGONLY's method also sounds super dialed in and is a little more sophisticated than mine:)
    I take ridiculous amounts of clones in a year, so I try to reduce and eliminate any steps I can without compromising success rates or quality and vigor

    Good Luck
    MCC420, GANJA MONSTA, RG420 and 7 others like this.
  8. Soak the cubes in 5.5 pH'd water till they are all the way damp. I put a little rooting compound like (Rootamentary and Sea Green from Beneficial Biologies) mixed in with the water I soak the cubes in. Take ur cutting, dip in clonex gel, place in rockwool cube just untill you feel resistance. Put in clone tray and cover with humidity dome ( I spray dome with some plain water to get the humidity up, clones take in their water thru the leaves while they are cloning and have no roots), place on heat mat on LOW setting. Leave em be for 3 days with dome on. After 3 days take dome off and just wait till you see roots. I run my T5s 24/7 early in veg and over my clones. I get 100% success in rockwool in 10-14 days using this method.

    Also... if your mother plant isnt healthy when you take cuts it will be harder for your cuts to root. YOU MUST have a healthy plant mother plant (or plant period) that you take cuts off.
    Medusa and marski420 like this.


    The reason you pre-soak in a 4.0 or so PH solution is to balance the PH within the rockwool cube. Rockwool is naturally alkaline. Therefore, to bring it to an acidic level (we are shooting for between 5.8 and 6.1 ideally) we presoak in a very acidic PH. You will notice that the PH will have risen to like 5.5 or even higher on its own after a 12 to 24 hour soak. That's because the alkalinity of the rockwool raised the PH.

    Sorry, I forgot to mention I do use a dome. Like Wayne said, you don't have to, and if you don't rooting will generally take longer. I vent the dome after day 4 or so partially, then full vent after a week. Once roots appear the roof is removed.

    If you don't have a meter I'm guessing you're using tap and not R/O water. In that case I would say like 1 ml/gal of micro and 1 ml/gal bloom is what I would use. Hope you have a PH meter because if not its a shot in the dark as to your PH. Although PH wise with my tap and the additives I just mentioned I'm guessing the PH would come out at like 6.3.
    Samoan and kbellfoy like this.
  10. Here ya go.. should answer your question.
    ripped from Grodan's website:

    Grodan Stonewool is pH Neutral!
    It is a common misunderstanding that Grodan is alkaline and that one has to continuously adjust the pH, when in fact Stonewool is pH neutral.​
    The confusion stems from the fact that Grodan has some residual lime from production. Follow this simple procedure to remove this un-buffered lime. Begin by saturating the stonewool in pH 5.5 water ½ hour before use. There will be a rise in pH of about 1.0 from the residual lime dissolving. The final step involves flushing the "dissolved Lime" from the stonewool with your nutrient solution just prior to planting or sowing. From this point onwards, the pH neutral Grodan Stonewool will not contribute to any changes in the pH of the solution.​
    Note: Ensuring pH values remain between values 5.5 – 6.5 is essential for optimum plant development and optimum substrate integrity. If you condition Grodan products with a solution pH lower than 5.0, you risk damaging the Stonewool, so take steps to ensure values do not go below pH 5.0​
    Why does pH change ?​
    When the plant grows the pH goes up because of the root activity involved in nutrient uptake of the plant. If the pH is not going up, your plant is not actively growing!​
    When the plant gets ready to set flowers or fruit, the pH will briefly drop. So when you notice this drop, the plant is signaling that it is time to change to your bloom-solution.​
    So in answer to your questions; You should always stay above pH 5.0 (better to use pH 5.5), because Grodan begins to dissolve below pH 5. You can soak the cubes on your table. You don't need to cycle, as long as the cubes are soaked initially. However, you do need to add the final step of watering from the top in order to flush out the lime residue. You should also get rid of the drained water, as it contains the lime residue.​
    MCC420, Samoan, seaslug and 4 others like this.
  11. Alright, I understood the first time then I was just confused by the 4.0 and 5.8 thing. I dont have a digital PH meter but rather just a little tube with drops, they work great for their price. I just fill about 6ml of this small tube up and put 3 drops in it.. the color of the water tells you(roughly) the PH. Having said that I do actually use R/O water so what do you recommend for the light solution? maybe 2ml per gallon each?
    ShroomKing likes this.
  12. Awesome information bro, thanks a lot!!!
  13. ralphy



    Too much moisture and those cuttings will simply rot.
    TrichromeFan and marski420 like this.
  14. I say Waayne has got it.

    It's probably too much moisture and not enough oxygen in the cube.

    marski420 likes this.
  15. Medusa

    Medusa Trichome Engineer Supporter

    I seed and clone in rockwool and a aerocloner works well for me . Fun how everyone uses dif ways and get dif results. The clone has been nicked all the way up the stem on the outside.
    MCC420, ShroomKing and bigcheese510 like this.
  16. I use rockwool and love it! I cut at a 45 degree use clonex then put it in the rockwool. If your in soil there is no need to soak rockwool in 5.6 ph water cause the ph is already 7. Put cut in the dome and close the port holes on top and fill tray with water, open ports everyday on top to let rockwool dry out that's what the ports are for use em, when they get a little dryer add some water so they don't get too dry lol and leave them alone don't touch the clone to see if it has roots just wait till you see them coming out of the rockwool :) I've heard a lot of stories lol people ask y didn't my cuts root out I ask what did u do they tell me their process and then they say I pulled the cut to see if there were roots then put it back when there weren't lol its hard not to laugh in your friends face but the things people do!
  17. OGONLY


    Good info there bro thanks. When using Grodan cubes I will adjust my tecnique for sure. I wonder though about the Pargo rockwool, is it the same deal? Grodan sounds like they are trying to clarify that their rockwool (stonewool) is not like the others as far as alkalinity is conserned.
    cheaplastic likes this.
  18. I tugged on a couple of the cuts, a couple felt snug but a couple others were pulled out but had little hard white... best word that comes to mind is nubs lol
  19. Chobble


    I try to wait two weeks before I even touch a clone Im trying to root. That way you won't disturb the very delicate root system, it kind of sounds like thats what you did.

    In my experince after two weeks though 90% of my cuttings (atleast) are rooted. Keep them warm and moist but not to moist and you'll be fine.

    I've even stopped using rooting hormones, They plant generally does it naturally. You don't need any fancy techniques.

    Be Patient!

    marski420 likes this.
  20. Its been 12 days and today is the day I tried pulling on them to see if there was any progress. I also made sure to mess around with the males I sexed out and left the females alone. Im also going to be taking more cuts tomorrow morning of more for sure females. One of the tiny male clones I didnt need for sure had roots until I picked it apart looking at it. I think I have this under control now thanks everyone for chiming in. When I get my first female to root Ill post pics.