3. After 24 hours have passed, fill up another bowl with 1 litre of water. Add your organic nutrient solution, fungi, and bacteria to the bowl in the quantities stated on the instructions. Soak the blocks in the solution for another two hours.
Yes! Rockwool contains basalt, which works great as a soil amendment in general. Once it becomes weathered over time, it releases nutrients such as phosphorus into the soil.
If you’re growing a photoperiod plant, you’ll need to switch your light cycle to 12 hours on and 12 hours off to force them to flower. If you’re growing outdoors, nature will take care of this for you. Keep autoflowering varieties on a light cycle of 18 hours on and 6 hours off if growing indoors.
Rockwool cubes are naturally alkaline. Because cannabis plants prefer slightly acidic soil, growers have to stabilise the pH of their cubes before sowing seeds (you’ll find out how to do this below).
2. Nourish your cutting: Dip the cut tip of your clone into rooting gel to expose it to rooting hormones, nutrients, and trace elements.
A combination of basalt rock, fast spinning actions, and extremely high temperatures are used to make Rockwool. The process starts with a combination of basalt rock and slag recycled from the steel industry.
Technically, no. Because Rockwool contains no organic material, microbes such as fungi and bacteria won’t break it down in the same way they would food scraps, leaves, and twigs.
In this lesson, we will learn how to start your own seed with Rockwool Cubes. Below is a detailed guide to success with Rockwool, and a step-by-step video tutorial can be found at the bottom of the page.
Some people claim they use a diluted nutrient solution to water their Rockwool cubes with during germination. Do not do this, as my experience has always been negative. Note the picture below, where I did an experiment by adding a very diluted grow nutrient to the Rockwool cube on the far left. It died within an hour or two, and the others went on to live happy lives. In my opinion, they do not need nutrients until they get into your hydro system.
Important: Do not let the PH of the water go below 5. A Ph this low will damage the fibers of the Rockwool Cube
Rockwool Cubes have a PH of roughly 7.8. This is pretty alkaline, yet our plants prefer to grow in a slightly more acidic environment (between 5.5 – 6.5). In order to prepare our Rockwell cubes for the seeds, we need to soak them in some PH adjusted water, that way they have everything the seeds need to germinate and sprout; water and a slightly acidic environment.
Items you will need:
About 2-3 weeks after germinating, you are ready to transplant these babies into the hydroponic system of your choice. A good rule of thumb to go by is that you want to transplant them once the first roots begin poking out of the Rockwool cube. Don’t wait too long though, as eventually the roots will begin tangling around the cube since it is their only source of water. You want to catch them right as they pop out, so that when you transfer them into your hydro system the roots will grow down into the system, and not just try to feed off the Rockwool cube alone.