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Help Starting Seeds In Rockwool

Discussion in 'Hydroponics / Aeroponics' started by nashvillekyle, May 16, 2008.


    nashvillekyle Active Member

    I am not sure I have done this right. I soaked the rockwool cubes for an hour in a nutrient mix. the mix was 1/2 gallon of water pH between 5 and 6 and 1/8 teaspoon of GH Micro and Gro. I put the seeds directly in 6 of them and in 4 of them I put seeds that i germinated on a paper towel. I then put the cubes in a big ziplock bag under lights 24hrs a day. My light setup is 4 4ft florescent tubes and 4 CFLs all 6000k. It has been a week and only one has sprouted and it was one of the seeds I didn't germinate. Not what I expected.
    My question is have I done this right or is there something I am missing? Also, when can I move the one that has sprouted to the hydroponic system?
    Any help you guys can give me would be much appreciated.
    ultimate procrastinator

    ultimate procrastinator Well-Known Member

    I'm pretty sure you don't want to have any sort of nutrients for seed propagation. Seeds only need their own food to sprout. Any extra may kill it.

    nashvillekyle Active Member

    Thanks I will start another batch with no nutrients and see what happens.

    pnseekr Active Member

    Kyle...take some paper towels and dampen them and place on a saucer. Spread the seeds over it and cover with another damp towel and cover that with another saucer. Place in a warm (not hot) dark place and check on daily. Make sure paper towels stay damp (not soaked). Give them 4-5 days and they should pop...then place in rockwool. No nutes for a couple of weeks at least. Then add nutes 1/4 strength until you see good growth and add more a week at a time.

    Hydrotech364 Gen Mod

    If I've said it once I've said it a thousand times,saying that nutes are bad for seedlings is like saying that a seed will not grow in fertile ground!!!!!
    i soak my seeds in a mild nutrient solution in a folded cotton towel you can get at any auto parts there blue and you can find them in rolls pretty cheap.i put them in a metal tin and place it in my grow room under lights with lid on.my seeds are always sprouted within 48 hours with the majority sprouting in 24 hrs.you don't have to leave the rock wool soaking.just splash them as this will leave more o2 in the cube.plant the seeds a lil over 3/8 of an inch in the cube.2 to 3 days later there up don't water or re feed until the cubes get lighter{in weight}then you're going good.i have also sat and sanded the sharp sides of the seeds with a fingernail file til there smooth ,this makes it easier on the seedling to split the hull and leaves less chance that the hull will be locked around the leaves of the seedling.:joint::mrgreen:Peace
    glani and d7b like this.
    ultimate procrastinator

    ultimate procrastinator Well-Known Member

    I've read from a few places that using nutrients on seedling is very risky and if you do it should definately be less than 1/4 strength. And using nutrients to germinate? None of the germination guides I have read suggest using any kind of nutrients for that. Just water.

    Hydrotech364 Gen Mod

    I have read that the sky is blue when its really just a reflection of the sea Marijuana is evolving so should the growers.
    Last edited: May 17, 2008
    7sugar likes this.

    Str8y180 Active Member

    on good advise i use clone FX seedling/cutting spray. Contains micro elements and vitamins for seed germination. Avoid full on grow nutes till about a week old.
    To return to the original thread, why are you putting the rockwool cubes in ziplock bags dude? no wonder there not sprouting theres no fresh air. Use the zippy to germinate in wet paper towell then let em breathe in moist (not wet or soaked) rockwool cubes.

    BLumen Member

    Just as a rule of thumb, never germinate with nutrients. Some say it works, and it may, but there is a risk. Why risk a process in a most fragile state of your plant's lives? Would you give a newborn baby a T-Bone steak? Not unless you are retarded.

    Get a small Tupperware container and add some pH friendly water to it. If you have a refrigerator or a water filter on your sink, this will make for a good, balanced pH for the most part. Just around 5.25-6 pH on the water alone will work best. Feel free to use distilled or bottled water, however you will soon find this to be like using Huggies brand diapers for a baby to shit in when the Kroger brand would contain the excrement just fine. Add the seeds you are intending to sprout into a folded up paper towel and place it in the bottom of the Tupperware container. Add the pH friendly water enough to soak the paper towel and have a couple of centimeters accumulated at the bottom of the container. Pop the lid on half way, leaving just a small crack for fresh air flow. Place in a dark place, such as a closet, and prop the container at a very slight angle so that the water will still keep the seeds wet but not completely submerged. Room temperature or slightly warmer will do just fine. Now, the hardest part is to leave them alone for about three days. The number one rule of growing next to keeping your mouth shut is to have patience. You can check them once or even twice a day if you must, lifting the paper towel to observe them and give them some fresh air. Just make sure to keep them in the dark as this will make the new plants search for the light they so desperately yearn for.

    Once the sperm tails are finally showing, you know that you are almost ready. Place them back for 24 more hours and they are now good to go! Take out your Rockwool cubes and throw them in a bowl of the same pH friendly water. Leave them alone for a couple of hours to let them soak and become saturated. When you go back to pick them up, set them on a plate. Also, the paper around them can come off at this point if you are planning on placing them inside of some Hydrotron (Lecca/Clay Pellets) and net pots. They can go directly into the net pots like this, or you can leave the paper on for now and stack the cubes in rows on a tray that has a plastic cover and let them sprout there. When placing them on this tray, you may want to use enough perlite to cover the bottom of the container that the cubes will rest on, and just add a little water to moisten it up. This will keep perfect moisture and air underneath the cubes to support the root development, and they can keep this way for a longer time than if you did not use the perlite. Remember, do not add any nutrients at this point!

    If you added the seedlings directly to the net pots or other medium in which they will develop, you will want to try and use some upside down plastic cups to act as a temporary greenhouse for moisture.

    Be sure to mist or water the cubes lightly two to three times a day to keep them moist, and if you are using a Bubbleponics or other hydro system that distributes water into the net pots, just let it run this way with pure, clean water--no nutrients.

    And there you have it. The seedlings can stay on the germination tray for a week or more if necessary, however it is best to get them into the net pots or growing medium once the roots are springing out of the bottoms of the cubes. Remove the paper from the cubes when you go to place them into your medium. If you are using net pots, do not add your 1/4 nutrient mixture to the water until roots are coming out of your net pot(s). This procedure will work every time if you have healthy seeds. Happy growing!

    Yours truly,

    highpsi Well-Known Member

    With all due respect, some of you are unnecessarily complicating the germination issue. It's really a simple matter. Wet (don't soak) your medium with plain water (PH if necessary), poke your seeds into the medium about 1/4 inch deep so that the seed lays side on, then put them in a warm place (around 25*C), light isn't necessary until the seedling actually pokes through the medium. You should see sprouts within 3 days. Always 100% successful for me.

    The paper towel method certainly works as well, but you run the risk of damaging the delicate rootlet while transplanting into your medium. This is basically an unnecessary step unless you are running a breeding program or using old seeds that have a lower germination rate.

    Germination needn't be complicated. Could you imagine if farmers actually had to go though these steps to germinate their crops? They'd never get anything done!

    Here is a link to the best guide I've ever read on germination: http://www.mandalaseeds.com/html/germination.html
    PeaceFarmer likes this.
    ol hippy

    ol hippy Well-Known Member

    Nicely put !! I used my bubbleponic set up and dropped the seeds right in the damp rockwool cubes with the drip lines on them they popped in 48 hrs all six...

    onomado Member

    For those of you who are trying to keep it simple... here is what has worked like a champ for me over and over....

    Soak your seeds in PH correct water (I use a shot glass) overnight. After that, dampen (dont soak!!!) a paper towel and lay the seeds in a line across the towel. Place the towel in a zip lock baggie and place it on top of your fridge (for warmth). My seeds always show the taproot within a day and a half. After you see a white tail on the seed, place it in your grow medium tail down. Period.

    hornedfrog2000 Well-Known Member

    That isn't true, but I did hear that when I was little too. Has to do with water droplets reflecting the blue spectrum of the light scale.

    I know this is old, but whatever.

    JonTheBaptist Active Member

    What if you remove the rock wool from the paper it came in? Why is it important that you don't do so?

    KingKong777 Member

    Alllllll seeds have the potential to sprout unless they have not developed properly within the seed. I had to fail many times before I got it right!

    All you need to do is this fill shot glass 3/4 way up with purified water. Place 2 seeds in and place the shot glass on a laptop battery pack that is turned on at all times. Leave laptop on and swtich on at light swithch so the battery pack stays warm at all times!
    Place on with teatowel doubled over the shot glass so everything is well and truly covered so the heat stays in. Leave for 3 days and the root will come out enough bout 1-2 cm so you can put straight into a rockwool cube. Place a small hole in the rock wool cube and put the germinated seed straight into the rock wool cube. Leave for one day covered over the batery pack. Once it has rooted prop add soil on top gradually this will give you a 100% germination rate FULL STOP THATS ALL ITIS EASY:hump:

    PeaceFarmer Active Member

    I'm with highpsi. This is exactly what I do, but first I soak the seeds in water for 24 hours. Then put them straight in the RW. I do tend to keep them in the dark until they have popped out of the RW, which is usually 2 days if soaked, or 4 if I don't. Also, Remember RW has an extremely high pH and should be soaked in water that is about 5.5 for at least a couple of hours. Ignore all of this nute will kill them BS, im not sure where people made this shit up from, but as a reference, if fertilizer kills seedlings, why do we put a handful of 10-10-10 with every seed in the garden? Corn, beans, tomatoes, peppers, they all get a handful right underneath the seed...it actually gets laid directly on the fertilizer. I guess that kills them huh...not at all, they grow beautifully. Just keep your nute solution diluted down a bit...no more than 600-800 ppm for the first week. Your rate of growth in the first week will be double that of people who dont use any. Good luck buddy.
    glani likes this.
    Fred West

    Fred West Member

    I did have six seeds sprout on me under two nice purple 24w flouros and just gave then correct ph water for first week like people keep saying "no nutes"...thats a load of bull there is no nutriant in the rockwool starter blocks and there is just about enough the the seed to make it crack and sprout. give em 1/4 rhysotonic as a soak then after a week start to use 1/4 strength a and b veg nutes.. otherwise like me the little buggers will just keel over and stave!!

    missinformation everywhere on this site!!!

    pazuzu420 Well-Known Member

    You can check the veg thread in my sig for examples of my method but I"ll explain it here. Everyone knows how to germ seeds in paper towel, if not stop now and don't do anything until atleast you how to do that. I soak my rockwool (grodan) according to the manufactures instructions. Soak for 20 to 30 min Ph'd water to 5.5 then take cube and with a quick flick of the wrist remove excess water, but never squeeze the cube as it ruins the water holding and shedding properties of the medium. I then open up the little hole and drop the seedling in tap root first. Then agian according to the instructions I wait 48 hours to even think about watering the little cubes. When I do water I water with 5.5 ph'd water applied with a turkey baster or a little plastic Ml. medication syringe so that I can watch and control exactly how much is going onto the cube that is, just till it changes color and water just begins to run out of the bottom. Placed in a shallow tote I was able to cover it with plastic wrap to control humidity by removing or peeling it back a bit. If you accidently water too much just pick up the cube and give it a quick flick.
    I would go 18/6 as they need some rest and tap water contains enough food while it has it's small little round leaves. Feeding can begin right before they begin to yellow. Within a week or so you should see plenty of roots comming out of the bottom (see previous mentioned thread).
    Oscar Zeta Acosta

    Oscar Zeta Acosta Active Member

    Do you direct the sprout from the seed up or down in the rockwool when transplanting from the wet paper towel?

    ANC Well-Known Member

    I burned a bunch of seedlings this last batch with 1/3rd strenght kelp.... two so badly that the growing tip died and went straight into two colas with retarded growth and one with a sensitivity or inability to handle one of the elements, makeing it into a polkadoted dwarf.

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