-Luis Guerra-
In my last submission for the Fifth Season blog, I spoke about three types of media used in hydroponic growing: Canna coco, expanded clay pebbles by Hydrocorn, and Sunleaves ‘Rocks.’ These are all great choices, but they are not the only options available. This post will cover three additional growing media for use in hydroponic growing.
Let’s start by talking about rockwool. Produced by heating basalt rock and chalk into a molten lava, rockwool is then spun out (sort of the way cotton candy is made) and cut into its final form. Rockwool is definitely a plant-grower’s friend as it holds its shape well and is available in various sizes, depending on your plants’ needs. It has a low buffer capacity, which means you can regulate the nutrients being delivered to your plants better. It holds water fairly well but maintains about a 25% air ratio even when over watering does occurs. Being that rockwool is alkaline by nature, we recommend soaking in a 5.5ph solution prior to using it.
Growstones are 100% Made in the USA. They are made from recycled glass bottles which makes them a 100% renewable source. Growstones are virtually indestructible and, unlike perlite, you will not find dust particles at the bottom of the bag. They are great at wicking and can absorb 30% water within the stone. They come in various sizeswhich they classify as G-1 and G-2. They also work at the root zone in eliminating fungus gnats – bonus!
A small number of growers use a 50/50 perlite-vermiculite mix to grow their plants. Vermiculite will hold water and nutrients, which are then available to the plant when needed. Perlite is mostly used for drainage purposes, meaning it creates spaces for air to reside so the roots can breathe. This media mix is an easy way to start messing around with hydro with products you can pick up at any garden store. Hand-watering a mineral based nutrient, or drip feeding works well with this media.
I hope this comparison of a variety of growing media has been helpful when you consider growing hydro. As always, we are happy to answer any questions you might have about media, systems, lighting, feeding, or anything else having to do with indoor growing. Just come on by and let us know how we can help!
mineralwool says
This post was very useful. Can I use it?
ashley says
Use it for what?
TK says
Part of what is great about growing in a 50/50 blend of Perlite and Vermiculite is also that this media has very little in the way of cation exchange sites so it doesn’t tend to play havoc on the nutrients you’re feeding your plants. What you feed is what the roots will see. It is important also to choose a large enough container that will allow enough nutrient/water holding capacity when the plants are full size and growing well. If you go to small it will lead to drying out between waterings. Cheers