Rockwool - Seedlings and cuttings - Need advice pls.

[CannabisDog]

Rockwool holds quite a bit of air even when wet. I still get rot in seed starts and in clones if it's too wet. They say damp after days and I don't have to water again. I am sticking to squeezing if I find the cubes get dry I will just water them after a couple of days. I think the more O2 in the cubes the better for the rooting process to happen.

 

[hippydan]

@Jedi: Do you think it's the pH adjustment of the cubes or the 0.2EC worth of nutes that is making the difference? By no means am I asking you to start yet another experiment, I'm just throwing the question at you. Thanks again, you've helped me immensely already! Thank you. Stay safe!

 

[kstampy]

I pH to 5-5.5 and do a 15m - 24hr soak depending on life lol, I don't adjust pH in that time. I do not use a dome and have RH of ~25-35%. I go about 14-21 days with just plain RO water until they have a good spray of roots, generally getting roots poking out in 7-10 days average. Then add around 700ppm of nutes after if I don't transplant in to soil that has nutes in it already, those get more plain water for a week or less. Watering from the bottom as little as possible is the best way to use them, I dip just the bottom in for a second or less and they stay wet about 24 hours. You are aiming for 4x the weight of a dry cube when watered. Don't squeeze your cubes, you will eliminate air in the medium and overwater/drown/rot your cuttings more often. I like to either whip my wrist to get out the water or do a lil trick that I found out accidentally recently. Stack them about 8 high and they wick the water down from the top to bottom, pull the top one when it is about right and keep going. You only have to whip the last few of them . Someone suggested a salad spinner even (I'll be trying that some time). Too much water is RWs worst enemy. Heating mats do wonders for RW as well regarding seeds and cuts and amount of time spent. Oh yeah and I never use the middle hole they provide for cuttings, works great for seeds though. The only clones that die on me is when I check too late or missed one while watering a batch.

 

[CannabisDog]

Squeezing the cubes works just fine. Never had rot once. They root 100% in the same amount of time. See what works for you and go with it.

 

[Jedi]

@Jedi: Do you think it's the pH adjustment of the cubes or the 0.2EC worth of nutes that is making the difference? By no means am I asking you to start yet another experiment, I'm just throwing the question at you. Thanks again, you've helped me immensely already! Thank you. Stay safe!

HI .

I,m about to do another experiment tomorrow with different levels of PH and ec.

Got a few seeds cracking , but i,d like a bit of a root to make sure i plant rooted seeds(and not dud's)
will post results in a few days !


My guess is the PH makes the difference for seedlings .
but if you add nutes , you also lower the PH at the same time....... win-win situation

 

[Scrogerman]

its 5.5 mate for RW(seedlings), never failed me, Ionic is a great starter nute, i think using a milder NPK fert with starting in mind is important. A heated propagator is the most important bit after youve soaked & charged the cubes.
EC 0.2-0.4 works for me, never lost one in RW & a heated prop!

I prefer to start seeds in wet paper, then once sprouted, tap root(10mm) down into RW cube, gentle push to suface so you can just see the seed & into the prop, misted Lid, 80-90% RH, 80f or so. never failed me once, you can see the moisture in the cube just by looking at it but picking them up is a good idea, check daily. Cubes shouldnt be drying out in 1 day, & wont in that humid environment, if they are its either too hot &or the moisure is escaping to quickly. Once my sprouts come right up, usually the next day i open the vents on my prop to regulate RH down to 60% over a couple of days. seedlings & plantlets need weaning out of higher RH's, dont just drop em out of 80% down to 50%, do it slowly so the plant can adjust.

 

[Jedi]

i prolly wouldnt squeeze the cubes into those trays. not that it wont work, but i'd rather let some air get to the bottom of the cubes. the taper of your tray is just pinching them slightly at the bottom while restricting some airflow.

you'll prolly be fine but since we are discussing the subtle details i'd just add a little suggestion.

Word !!!
the cuttings in cube trays rotted . !!
probably had them under the humidity dome too long

the cuttings without trays are still fine (touch wood)

 

[hippydan]

March 14th I soaked 4 seeds for 12 hours in room temperature bottled water, ~50ppm. I pre-soaked my rockwool starter cubes in water adjusted to pH 5.5 (This is my tapwater that is already 400ppm so I didn't add any nutrients whatsoever, ew). I then shake out a reasonable amount of water, making sure the cubes are moist, but not soaking wet or completely dry. I just haphazardly dropped the seeds into roughly 1/4" deep holes I made into the cubes. I make sure to cover the hole afterwards with a small piece of rockwool, but I did not really plug the hole. A day later all seed husks have cracked open and the taproot is visible. I thought it might be a problem considering all my seeds were upside down and the taproot would have to grow around the seed itself before it grew down into the rockwool, but I figured Mother Nature would do a better job than I, so rather than go digging around the cubes I let her do her thing. I've already witnessed a few of the seeds turning around in the holes and I'm pretty sure tomorrow, all four will be poking their heads above the rockwool. So easy, even I could do it! I didn't bother taking pictures because really, all you'd be looking at are seeds soaking in shotglasses or rockwool cubes.

 

[Jedi]

March 14th I soaked 4 seeds for 12 hours in room temperature bottled water, ~50ppm. I pre-soaked my rockwool starter cubes in water adjusted to pH 5.5 (This is my tapwater that is already 400ppm so I didn't add any nutrients whatsoever, ew). I then shake out a reasonable amount of water, making sure the cubes are moist, but not soaking wet or completely dry. I just haphazardly dropped the seeds into roughly 1/4" deep holes I made into the cubes. I make sure to cover the hole afterwards with a small piece of rockwool, but I did not really plug the hole. A day later all seed husks have cracked open and the taproot is visible. I thought it might be a problem considering all my seeds were upside down and the taproot would have to grow around the seed itself before it grew down into the rockwool, but I figured Mother Nature would do a better job than I, so rather than go digging around the cubes I let her do her thing. I've already witnessed a few of the seeds turning around in the holes and I'm pretty sure tomorrow, all four will be poking their heads above the rockwool. So easy, even I could do it! I didn't bother taking pictures because really, all you'd be looking at are seeds soaking in shotglasses or rockwool cubes.

Cool man , glad its working for ya.

I also got some new seeds in RW......

coming along nicely !

 

[t33to]

March 14th I soaked 4 seeds for 12 hours in room temperature bottled water, ~50ppm. I pre-soaked my rockwool starter cubes in water adjusted to pH 5.5 (This is my tapwater that is already 400ppm so I didn't add any nutrients whatsoever, ew). I then shake out a reasonable amount of water, making sure the cubes are moist, but not soaking wet or completely dry. I just haphazardly dropped the seeds into roughly 1/4" deep holes I made into the cubes. I make sure to cover the hole afterwards with a small piece of rockwool, but I did not really plug the hole. A day later all seed husks have cracked open and the taproot is visible. I thought it might be a problem considering all my seeds were upside down and the taproot would have to grow around the seed itself before it grew down into the rockwool, but I figured Mother Nature would do a better job than I, so rather than go digging around the cubes I let her do her thing. I've already witnessed a few of the seeds turning around in the holes and I'm pretty sure tomorrow, all four will be poking their heads above the rockwool. So easy, even I could do it! I didn't bother taking pictures because really, all you'd be looking at are seeds soaking in shotglasses or rockwool cubes.

Nice to hear you had some success man. What the hell is in your tap water? Well?

 

[hippydan]

Nice to hear you had some success man. What the hell is in your tap water? Well?

I wish I still had a well! Back in my hometown my wellwater was ~60ppm and tasted great! I'm currently in a city and afraid to ask(figuratively speaking of course). Going to get a filtration system very soon, I don't want to drink the stuff anymore as you can imagine.

 

[t33to]

I wish I still had a well! Back in my hometown my wellwater was ~60ppm and tasted great! I'm currently in a city and afraid to ask(figuratively speaking of course). Going to get a filtration system very soon, I don't want to drink the stuff anymore as you can imagine.

City water? Woah. That's crazy to think city water can have that much stuff added into it. I hope it's all calcium, lol. You going for reversed osmosis?

Btw, I just beat my rock wool clone record. 6 days for a root to shoot out of the cube

 

[Jedi]

Today is a very happy day for me regarding Rockwool(GrowDan)
Seedlings are happy and roots are poking through from the cuttings after 10 days !!!!


I mean , it even carries my name ...... It was like the Voice of the Universe speaking to me !!
Grow Daniel San !!!!!! GROW !

Pre-soak in 0.2 ec / PH 6........shake all water out , plant seeds / cutting.
BANG...No worries

 

[Jedi]

Double post

 

[hippydan]

Hey Jedi! Thanks for the update. It's been a couple days since I dropped my pre-soaked(for 12 hours) seeds into the GroDan 1"x1" cubes. I just want to start by saying it was a NIGHTMARE. The seedlings had a hard time penetrating the rockwool, and rather than the taproot grow down into the medium, it pushed the seeds out of the hole. This was my mistake as I didn't plug the hole to keep enough pressure on the seeds to force the roots down into the rockwool. I really didn't want to go digging around the cubes, in fear I might damage the seedlings. After about an hour trying to play Mother Nature I had enough and said, "**** it, it is what it is". Well, a couple days later and after four of four seeds germinating, all four seem to have survived the rockwool episode and are dark green as well as throwing out their first sets of true leaves. I thought two of them were goners for sure, but they proved me wrong. This experience has made me really dislike rockwool. Sure it's "easy", and it did give me a perfect germination success rate, but it was very stressful as far as growing plants goes. Definitely not something I would be comfortable to "set and forget". Had I not been around 24/7 to keep my eye on them, I don't think I'd have 4 plants right now.

Cuttings on the other hand, I think will do great in the starter cubes. I'm still not sure I will be using rockwool for seedlings in the future, however I can't argue with my results. I'm just trying to let the other newbies(like me) out there know it's not as foolproof as it looks.

* I pre-soaked the cubes in 5.5pH water @400ppm(.5conversion) tapwater, no nutes added.

 

[Jedi]

hey coolios for your experience !!

My only dislike is you cant top it up like soil .
I got these long stems and afraid that they gonna fall over , perhaps a bit of support and maybe they will ....'harden the fuk up !!' lol

Its just so light , mobile and easy to squeeze loads of seeds and clones in a small space.

 

[hippydan]

Its just so light , mobile and easy to squeeze loads of seeds and clones in a small space.

I agree! I think I'm slightly bias because I've only ever grown in soil, and it was truly foolproof. I spent over 3x my seed budget than I had planned on this grow, and if I wasn't so anal about my babies surviving, I think I might have a different perspective on the rockwool. I plan on making a few seeds this run, so I'll definitely be experimenting with rockwool in the future to try to figure out how to refine my methods. I want to say thanks again, Jedi. You helped me immensely.

 

[Jedi]

Hey dude , it gives me great pleasure to be of help to somebody , then again many IC members helped me a lot .
I,m just spreading the info !

Feel ya man
I also failed many-many seeds and cuttings the last month or so , experimenting with different mediums.

Soil ....too messy and inconsistent.
Coco......no luck
Perlite....dries anything out too quickly
Even my earo cloner started giving me root-rot in summer . (but i fixed the ole pathogens)
I even had my Mother planting a few for good measure.

Nothing gave me exceptionable results like i did in the past !!


My main rig is Aero and i,m always just cloning off mothers so i was left with 3 plants in Veg.
Usualy i just make clones and my Cloner stated failing on me from extreme heat .

Stressed out quite a bit and almost stopped growing from not getting anything going ! LOL

This Rockwool stuff have restored my faith in growing .

 

[Scrogerman]

Hey Jedi! Thanks for the update. It's been a couple days since I dropped my pre-soaked(for 12 hours) seeds into the GroDan 1"x1" cubes. I just want to start by saying it was a NIGHTMARE. The seedlings had a hard time penetrating the rockwool, and rather than the taproot grow down into the medium, it pushed the seeds out of the hole. This was my mistake as I didn't plug the hole to keep enough pressure on the seeds to force the roots down into the rockwool. I really didn't want to go digging around the cubes, in fear I might damage the seedlings. After about an hour trying to play Mother Nature I had enough and said, "**** it, it is what it is". Well, a couple days later and after four of four seeds germinating, all four seem to have survived the rockwool episode and are dark green as well as throwing out their first sets of true leaves. I thought two of them were goners for sure, but they proved me wrong. This experience has made me really dislike rockwool. Sure it's "easy", and it did give me a perfect germination success rate, but it was very stressful as far as growing plants goes. Definitely not something I would be comfortable to "set and forget". Had I not been around 24/7 to keep my eye on them, I don't think I'd have 4 plants right now.

Cuttings on the other hand, I think will do great in the starter cubes. I'm still not sure I will be using rockwool for seedlings in the future, however I can't argue with my results. I'm just trying to let the other newbies(like me) out there know it's not as foolproof as it looks.

* I pre-soaked the cubes in 5.5pH water @400ppm(.5conversion) tapwater, no nutes added.

Hy HD,
Just thought id mention its pretty common for seedlings to pull themselves completely outa the RW cubes. You may have better success starting seeds in paper towel etc, then once you see taproot at 5-10mm(no longer), plant them up into the pre-reated RW.
You never plug RW cubes, seedlings will struggle to get out if you do that one, there shouldnt be any need to do it. I get myself a cotton bud(cotton removed) , or a toothpick & very gently spread the RW to gently cover the seed, or any hole size im not happy with.
Your Tap is hard man EC0.8 outta the tap is real hard man. You may wanna consider mixing your tap 50/50(or 75/25) with Di-ionised/demineralised/RO water to your tap water, I would definately be looking into buying an RO unit if my tap was EC0.8.
Try germing seeds in paper towels & then once you see a small taproot, make hole in cube or slightly widen with toothpick & plant them up, tap root down, seed should be either flush with the cube surface or just under, so you can just see it, into the heated propagator, within 36 hours they should be up, if not sooner.
This is my trusted method & ive never lost a seedling to date. seems faster this way too. i dont know why but when i try to germ seeds in RW prop cubes it takes 7-9 days in most cases. if i use the paper towel method then plant up into RW it takes 3-6 days for the same result. try it n see bro.
Hope that helps!

 

[hippydan]

Thanks Scrogerman! I'll definitely give rockwool another shot, it gave me 100% success rate so far. Just gotta get used to it's downfalls I guess. And yeah my tapwater is gross! I've been mixing it 50/50 with store bought water, and recently picked up a screw on Brita "tapfilter" that will have to do until I move. Once I'm in a more permanent location I'll definitely look into setting up an RO unit.

I soaked my seeds in shotglasses for 12-18 hours before moving them into the rockwool starter cubes, 12-18 hours later I saw the taproots poking through the seeds. It took another day for the bravest seedlings to poke their heads above the rockwool, and a day after that for the slower ones. Sounds like I was right on track with the results you get! Beginner's luck I suppose! I was afraid I was playing with them too much and might've damaged 1 or 2 but all are still alive and well. I don't have a heating pad but I kept them in a cupboard above my stove, and with the stove light on it was nice and cozy in the small cupboard.

In a perfect world I'd have mother plants started and grown in soil, and just veg/flower out the cuttings in the rockwool/DWC. Thanks again Scroger!