Tips - Germination and seedling phase in rockwool

I'm germinating a new seed in rockwool.
It's in a dome with a heat mat. I'm using PHd (5.5) RO without adding nutes. There are mixed suggestions on this forum and other websites on how to approach. I'm getting confused and would really need some advice as I'm a complete noob and already burned my first seedling :'(

Questions might be silly for most but helpful to get me on the right path.
1-Should I add nutes once cotyledons are out? If so, what do you recommend Vs advised feeding schedule? (25%, 50% or more than what's written on the package) I'm using GH trio
2-Shall I move my seedling to the DWC setup if it has 1 root or should I leave it in the dome until more roots come out?
3-Whats the distance between water and start of net pot? Should the water touch the rockwool cube once it's in hydroton?

Appreciate your support

The only tip you need:

Don't use rockwool. Period. Especially if you're a noob. You'll have nothing but headaches.
Instead, but root riot cubes that come within a tray of 24 or rapid rooters. They will give you success.
Rockwool simply just stays to wet or not wet enough, then eventually gets over watered anyways.
As for nutes, don't add them until your first set of 5 finger leaves emerge and are a good 2"x2" in size. Cotelydons have all a seedling needs stored in them for about a week-10 days. When you do add nutes make sure you're starting with 0ppm reverse osmosis water and don't go above 2-300ppms. And very importantly, make sure you ALWAYS mix your CalMag into the water FIRST.

Yes move the rockwool cube into your system, people have issues because they are forever wetting the cube which causes damping off where the stem rots, plant the cube pretty deep in the clay pebbles like half way down, if you fill res to just under the net pot you should get water wicking up through the clay pebbles so no need to water the cube.

MrGreenFingers99 said:

Yes move the rockwool cube into your system, people have issues because they are forever wetting the cube which causes damping off where the stem rots, plant the cube pretty deep in the clay pebbles like half way down, if you fill res to just under the net pot you should get water wicking up through the clay pebbles so no need to water the cube.

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If you're lucky... Rockwool just sucks up any and all moisture it can get until it's fully saturated.

Airwalker16 said:

If you're lucky... Rockwool just sucks up any and all moisture it can get until it's fully saturated.

Click to expand...

Totally agree which is why you should only soak it overnight once before putting the seed in, people have this thing about constantly misting them and keeping them soaking wet so there is no oxygen.

If you're seedling hasn't established roots into the cube yet and you can remove it, I suggest you do. If you've got an Aero cloner, stick it in a collar and use the spraying to fed it til it's tap roots 6 or so inches long and the plant gets some structure to it. Then put it straight into the hydroton bare roots. Just put it in thevenpty netpot first, bring the roots down close to the bottom so the stems buried a bit, and gently fill it while keeping it centered like you'd do with a freshly rooted Aero-clone.

MrGreenFingers99 said:

Totally agree which is why you should only soak it overnight once before putting the seed in, people have this thing about constantly misting them and keeping them soaking wet so there is no oxygen.

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Overnight soak will waterlog it way more than you want. I think if you're forced to use rockwool, the best way to get it the right amount of damp is with a spray bottle. Put it right up against the nozzle and spray it ONE time, in a couple different spots, leaving other spots completely dry. It will even out in a few minutes

Airwalker16 said:

Overnight soak will waterlog it way more than you want. I think if you're forced to use rockwool, the best way to get it the right amount of damp is with a spray bottle. Put it right up against the nozzle and spray it ONE time, in a couple different spots, leaving other spots completely dry. It will even out in a few minutes

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Depends on germination method I guess, I just keep it simple and soak the cube overnight, shake out any excess and throw in the seed, the cube is wet enough then for the whole germination process until the seed has popped and it's in my system, now if your germinating in a shot glass and paper towel method so the seeds already cracked and you have a taproot then I wouldn't soak it for so long as you say.

Airwalker16 said:

The only tip you need:

Don't use rockwool. Period. Especially if you're a noob. You'll have nothing but headaches.
Instead, but root riot cubes that come within a tray of 24 or rapid rooters. They will give you success.
Rockwool simply just stays to wet or not wet enough, then eventually gets over watered anyways.
As for nutes, don't add them until your first set of 5 finger leaves emerge and are a good 2"x2" in size. Cotelydons have all a seedling needs stored in them for about a week-10 days. When you do add nutes make sure you're starting with 0ppm reverse osmosis water and don't go above 2-300ppms. And very importantly, make sure you ALWAYS mix your CalMag into the water FIRST.

Click to expand...

That's clear instruction
Thanks @Airwalker16 , I am going to pick up a root riot bag and move my seed to it.
I do read elsewhere that CalMag needs to be mixed after mixing nutrients, I guess that's out of the question too.

MrGreenFingers99 said:

Yes move the rockwool cube into your system, people have issues because they are forever wetting the cube which causes damping off where the stem rots, plant the cube pretty deep in the clay pebbles like half way down, if you fill res to just under the net pot you should get water wicking up through the clay pebbles so no need to water the cube.

Click to expand...

Perfect, my first installation had the water surpassing the bottom part of net pot, drenching the rockwool in water. Not going to repeat the same mistake !!
Based on your advice, the air bubbles from the air stone should create a mist in the bucket that will help the roots absorb the water it needs, right?

Airwalker16 said:

If you're seedling hasn't established roots into the cube yet and you can remove it, I suggest you do. If you've got an Aero cloner, stick it in a collar and use the spraying to fed it til it's tap roots 6 or so inches long and the plant gets some structure to it. Then put it straight into the hydroton bare roots. Just put it in thevenpty netpot first, bring the roots down close to the bottom so the stems buried a bit, and gently fill it while keeping it centered like you'd do with a freshly rooted Aero-clone.

Click to expand...

I don't have an Aero cloner. Can I leave it in the root riot for 10 days in the dome until it develops most of it roots and then move it to the DWC?
Can I leave a layer of water at the bottom of the dome or do i need to spray it? if so, how many times do I need to spray it a day to avoid over watering.
Regarding the transition phase from root riot to hydroton (in the DWC setup)
Should I:
1- remove the root riot, clean the roots gently and place it straight in hydroton?
2- move the seedling to a rockwool and place it in hydroton?
3- keep the seedling in root riot and place it straigh in hydroton for the rest of its growth?

Afarah.86 said:

I don't have an Aero cloner. Can I leave it in the root riot for 10 days in the dome until it develops most of it roots and then move it to the DWC?
Can I leave a layer of water at the bottom of the dome or do i need to spray it? if so, how many times do I need to spray it a day to avoid over watering.
Regarding the transition phase from root riot to hydroton (in the DWC setup)
Should I:
1- remove the root riot, clean the roots gently and place it straight in hydroton?
2- move the seedling to a rockwool and place it in hydroton?
3- keep the seedling in root riot and place it straigh in hydroton for the rest of its growth?

Click to expand...

Leave the plant in the root riot. Once it's been in it for a few days especially 10, it will be.LAIDEN with roots. No chance in hell of removing it.
The hi idityvdome, just spray 2-3 times a day for about a week.

Afarah.86 said:

Perfect, my first installation had the water surpassing the bottom part of net pot, drenching the rockwool in water. Not going to repeat the same mistake !!
Based on your advice, the air bubbles from the air stone should create a mist in the bucket that will help the roots absorb the water it needs, right?

Click to expand...

Yep, as long as you have a decent air pump then spray should be coming off the water surface and wetting the clay pebbles, you can also take a jug of the res solution and pour it through the clay pebbles put pour it around the rockwool cube and not directly over it but I've never found it necessary

I see a lot of rockwool hate around here from you @Airwalker16 but I can assuredly say that I've never lost a seed and I've popped every single one in rockwool. I don't follow any crazy guidelines either, I drop a 1.5"x1.5" cube into a bowl of water (tap, not pH'd) for about 30 sec, I take it out and give it a shake (not a squeeze), I drop a seed in the hole, cover the hole, and then close off the block in some tupperware (or I use a ziplock bag). I'll burp it with fresh air every 24hrs until I have a seedling (usually a few days). It's so insanely easy and has never given me a problem going back to the mid 2000's when I started doing this.

Major Blazer said:

I see a lot of rockwool hate around here from you @Airwalker16 but I can assuredly say that I've never lost a seed and I've popped every single one in rockwool. I don't follow any crazy guidelines either, I drop a 1.5"x1.5" cube into a bowl of water (tap, not pH'd) for about 30 sec, I take it out and give it a shake (not a squeeze), I drop a seed in the hole, cover the hole, and then close off the block in some tupperware (or I use a ziplock bag). I'll burp it with fresh air every 24hrs until I have a seedling (usually a few days). It's so insanely easy and has never given me a problem going back to the mid 2000's when I started doing this.

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Thatscll fine and dandy. But for a noob, there are much more efficient ways for success, that's all

See and I choose rockwool bc I find it to be effortless (literally), consistent, and relatively cheap which is essentially the definition of efficient. I'm not invalidating other methods - paper towels, rapid rooters, etc; they're all good - but I can't get down with the idea that rockwool is by any means an impracticable solution (even for a novice).

Add water to mixture, drop seed, forget about it for 5 days, move to cloner, forget about it for 2-3 weeks.

You say its effortless and then talk about the steps you take? I bet you check them for correct moisture every time you "burp" them too huh?
Would you be comfortable ignoring them for a week or more? If not, you could do better.

Airwalker16 said:

Leave the plant in the root riot. Once it's been in it for a few days especially 10, it will be.LAIDEN with roots. No chance in hell of removing it.
The hi idityvdome, just spray 2-3 times a day for about a week.

Click to expand...

Just moved it to its new medium
Watching all the videos out there, I always assumed root riot would have a crumbly texture, a bit tougher than dirt.
It turns out to be spongy and resistant. Now I understand why there is no way in hell to move it to another medium once roots are well developed

I also replaced my 600W LED with 2 x 24W T5 HO based on another suggestion from this forum. The temperature is more stable in the room (22°c to 23°c)
Is there a recommended distance I should keep between the seedling and the light? Closer at first and further as it gets into a vegetative state?

fragileassassin said:

Add water to mixture, drop seed, forget about it for 5 days, move to cloner, forget about it for 2-3 weeks.

You say its effortless and then talk about the steps you take? I bet you check them for correct moisture every time you "burp" them too huh?
Would you be comfortable ignoring them for a week or more? If not, you could do better.

Click to expand...

Oooh you are fragile aren't you? Well I didn't mean to offend you there tulip, I only spelled out the minutiae of my process to be thorough. For many years of popping seeds I didn't actually place them into any kind of container or bag until my cat jumped onto my countertop and ate a seedling. In trying to protect them, I found that trapping the moisture also helped. So here, a revised version just for you; I put a seed in a wet cube and i keep it moist. Run along now.

MrGreenFingers99 said:

Yep, as long as you have a decent air pump then spray should be coming off the water surface and wetting the clay pebbles, you can also take a jug of the res solution and pour it through the clay pebbles put pour it around the rockwool cube and not directly over it but I've never found it necessary

Click to expand...

Yes and I have 2 airpumps just in case one breaks

I also have a water pump that came with my DWC setup but I don't know how to properly install it.
Since everyone's advice is to avoid drawing your plant, it felt impossible to place the water pump tube above or next to the medium without soaking it constantly thus beating the purpose of maintaining oxygen at all time.
I'll put this technique away for now and focus on simple methods like the one you suggested