Rockwool grow questions

[Jkrustie]

Heya

This is my first serious attempt with growing soiless in rockwool.
I've got some nice Diablo(Next Generation Seeds) seedlings in my 4"x4" rockwool blocks.

Growth looks good, and after 5 days going from the 1" cubes to the 4", the roots are starting to come through the bottom.

This is where I have a question, how long can you allow the roots to grow through the rockwool cube? I have them in a cloning tray, so the roots will presumptually grow in the tray, sucking up run off inside the tray after waterings.

Now...it seems to me that roots exposed to the air would need constant moisture to live, so does there need to be run off in the tray 24/7? Or will the dark moist area directly below the 4" cube serve as enough moisture?

I plan to transplant to a medium sized pot filled with Grodan Grow cubes, the tiny 1cm X 1cm rockwool cubes. I am going to be feeding as if this was soil, watering from above, the rockwool acting as soil would.

So how long can the roots grow into the tray, how soon should I get them transplanted into the pots?

I am also concerned about some discoloration on the young leaves. It looks like light burns, but I'm using cool white flouros. I observed the exact same thing last time I grew these seeds, and I thought it was light burn. Perhaps it's just the genetics? No pests, temps are perfect, feeding with Canna Substra Vega at 8mL per 5L water, and Rhizotonic at 20 mL per 5 L (min. suggested feed).

Other then that, how do they look, coming along for their age?

Pics won't upload.....

Thanks.

Jkrustie Reviewed by Jkrustie on 09-12-2006. Rockwool grow questions Heya This is my first serious attempt with growing soiless in rockwool. I've got some nice Diablo(Next Generation Seeds) seedlings in my 4"x4" rockwool blocks. Growth looks good, and after 5 days going from the 1" cubes to the 4", the roots are starting to come through the bottom. This is where I have a question, how long can you allow the roots to grow through the rockwool cube? I have them in a cloning tray, so the roots will presumptually grow in the tray, sucking up run off Rating: 5

[Jkrustie]

pics, had to convert to gif???wtf

[Jkrustie]

Mods please delete above post with gif images ^^^
Thar, these are the Jpegs ignore the above pics.

[Jkrustie]

Holy crap, does no one post here anymore?
bUMp

[floyd2zapper]

Hi jkrustie.

I had that problem recently i just filled the bottom of the tray with hydroton clay medium and had about 2 mils of nutrient solution at (cf 10) on the bottom for the roots to grow into the main reason i did this was was to protect the roots from the light.

Hope this helps .

[BlueBear]

If you are going to take out those babies how long do you plan on waiting? If the root ball becomes to large it may stress the little ones some when you take them out of the RW. Also, the grow rocks seem like a good idea, but remember the roots are going to need more water than the RW cubes so water them seperatly. If those cubes are always water logged you may run into root rott problems.
Adieu

[Jkrustie]

Thanks for your replies.
I allowed the tray to become dry over night and sure enough the root tips underneath have dried out. So I have to keep them moist it would seem.

Floyd, I have considered leaving a layer of solution in the tray, and covering it up with hydroton, which is a great idea, however Blubear makes a good point by saying excess moisture will cause root rot. I have Rhizotonic in the mix, which helps break down old roots and stops the growth of vertain fungus etc, but I don't like the idea of a constantly wet medium. Because of the capilarry water up take of the rockwool, leaving water in the tray will always be sucked up into the rockwool.

Bluebear I plan to keep them in the rockwool, and put them into a pot with rockwool already in it, like a soil transplant. So all the growth now is good.

I guess I'll have to just wait it out and see, it is too early to throw them into a pot just yet imo, so I guess a small % of the roots will die while the rest catch up. I don't want to transplant until there is a large amount of roots, for the simple reason that if i transplant now, the roots will shoot down again, and there will be areas above that don't develop as much as id like.

Any other ideas?

[floyd2zapper]

Hi Jkrustie.

It worked for me i might of got lucky though.Bluebear is a lot more experienced than me and i have had advice from him myself he knows his stuff.

Good luck with what you decide to do mate take it easy.

[Jkrustie]

Well my bigger seedlings were drooping a little on the outer area of leaves, so it looked like they needed more water. I'm not so experienced in rockwool so it's hard to tell how wet to go. The rockwool has always been moist, never dry to the touch, never light to hold up, and when I water i soak them through and through, is this correct? Last time I lost a number of seedlings because they dried out so damn fast, so I thought it was good to keep rockwool moist at all times.

I decided to give them a good watering, because what I hope isnt the signs of poor water up take due to rot, looks like they needed water to me.

I also added a barrier of tinfoil over the rockwool and the tray, to keep the light away from the exposed roots below.

I had some of the rockwool i need ordered today, but it won't arrive till this time next week....I don't know how long I can hold them out like this....
I might have to cut up some 1" RW cubes to serve as a trasnplanting medium.

decisions decisions.....

[floyd2zapper]

Jksustie.

What system r u going to put them in.