Most of us hydroponic growers have used Grodan rockwool in one form or another. The standard in Rockwool media, Grodan delivers. These blocks and slabs will give you the perfect water/air ratio and hold it for days if necessary. Excess water will immediately drain out of the block, holding only how much water the roots need, and they will hold this water much longer than modern planting media. You dont have to be a hydroponic grower to enjoy the benefits of this volcanic rock based media. You can easily start your seedlings or clones in them, and then transplant the whole block into a container of your favorite soil. This way, a rich nutrient solution will always be held within the block in the soil right where your roots want it.
The grow plugs they make for propagation are awesome. Many different rooting techniques can be applied using the rockwool plugs and some hormone. They are also perfect for starting seeds because of their perfect air to water ratio they provide. I have been seeing some different companies coming out with similar rockwool products, but I have not tried any other than rockwool besides grodan. There are plugs made of another material called :oasis" that I also use, but we will get into that in another post. Be well....
