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how to start marijuana seeds in rockwool cubes

Starting seeds in Rockwool

Soak rock wool overnight in 5.5ph plain water overnight before planting. You don’t need any nutrients until plant has true leaves same as any other media.

Be careful not to over water small plants. RW holds a lot of water and can damp off stems if over watered.

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  • Join Date: May 2008
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Soak rock wool overnight in 5.5ph plain water overnight before planting. You don’t need any nutrients until plant has true leaves same as any other media.

Be careful not to over water small plants. RW holds a lot of water and can damp off stems if over watered.

RW works great for germinating seeds ..

#1. Today’s RW is ph balanced and does not require extensive soaking to lower ph .

#2. Overwatering RW is just about impossible unless you just let it sit in standing water. After getting wet, RW will equalize to a balance of air/water in minutes. The idea that watering it a lot causes problems is just nonsense . sorry, but I hear it all the time on this board, and it’s simply nonsense.

As far as soaking . a light rinse is all you need (I didn’t even do that for years and it works fine).

RW delivers 100% seed germination for me in the vast majority of cases and works great. Keep moist . generally agree with the no nutes comments, but I find small, trace amounts, like less than 200 ppm, don’t hurt anything.

The biggest "trick" I think to germinating seeds is warmth . especially during winter, simply being in a heated house isn’t enough unless there’s a heat outlet right by it. I put a space heater, not letting it get too hot, right near the seeds/RW cubes and they germinate much better/faster.

See also  bulk feminized marijuana seeds

Rockwool Cubes in Super Soil?

I’m a Super Soil user, and I’ve been planting seeds in Rapid Rooter plugs for a long time. They work fine, but I’d like to try planting seeds in 1.5" rockwool cubes instead. Rockwool cubes are cleaner and stand up well on their own.

After sprouting, I would plant the rockwool cubes directly in Roots Organic soil, and eventually transplant into Super Soil.

Would these small rockwool cubes interfere with the natural PH balance of the soil? I really don’t want to PH-balance my feeding water. Nor do I want to PH-balance water in which to rinse the rockwool cubes before planting. The reason I switched to organic growing was to get away from PH-balancing.