Rockwool in dwc system

Can i use seeds with sprouts directly in dwc system in a rockwool ? Or i have to wait ?

Yes, but you’ll need to top feed until the roots reach the water.


Hi Amr. Welcome.

I think you’re asking if you can place a seed into a rockwool cube to sprout it. The answer is yes.

Like @Covertgrower mentioned, you need to water the cube until the roots hang down into your water reservoir. Usually, you’d place the cube in a basket with stones, and pump a constant trickle to the top of the cube with a Rain Bird type emitter. The water drips through the cube, back down into the bucket/tub.

Does that make sense?


Ok . How can i top feed ? . The seeds is alreary with sprouts and placed in the rockwool in the dwc system
I did put the neutrients in the water and the ph is 6

Ph should be 5.8
You have to water by hand, or have a pump on a timer.

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The rockwool already settled in the system with full water
Ill attach some pics for you . And lets see .

Ill attach pics and lets see
Thanks a lot

Anytime. Don’t forget to tag me @Covertgrower when you get her all fixed up.


Are you bubbling air into the water?

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Let’s hope they are! :man_shrugging:

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Yes i do bubbling

Okay, good. Just checking.

You only need a submersible water pump and water line. An emitter is nice, but not critical.

Do you have hydroponic stores you can go to, or Amazon?

Something like this would be fine:

Black tubing is better, but you only need the thing for a short time. Black is better at preventing algae blooms.

Seedlings don’t need nutrients the first couple of weeks of life. When you do introduce nutes, do so at 1/4 strength to start. Welcome btw :wink:

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Did you get that system used?

The rockwool looks different to me. Is that house insulation?

I’m a bit worried about how soaked your seeds are, even in aerated water. If things go bad, don’t try another seed until you have a pump set up and working. Then you want to keep the water level much lower.


@Southerngal if they’re in hydro, plain water has zero nutrients, they’ll need a low PPM of nutrients (200-500) after the first set of leaves come out.


I added nutrients when the cotyledon leaves start to die off. I’m also using regular tap water that has some level of stuff in it? It was about 10-14 days in before I added anything. Sorry if I passed on in correct info :neutral_face:

You’re correct it does have some dissolved minerals in it, but shouldn’t be counted towards the PPM of nutrient measurement. Tap water with 200 ppms doesn’t have any nitrogen in it, but most likely to have lime and calcium. So nutrients should still be added.
I was more trying to clarify your answer more than anything.
Happy growing :seedling:


Thanks! I learned something :wink: