Loading... Please wait...


Grow Mediums

Posted by

The practice of hydroponics allows crops to be grown without the use of soil, but that doesn’t mean that the plants are to be suspended in mid-air! Alternative substances must be used to provide root support, water supply, and other functions which would usually be imparted by soil, while dispensing with the inconveniences. These substances are known as grow mediums. Let’s consider a few of the hydroponic grow mediums available, with their advantages and uses.

Rockwool and Perlite

These two have been described as the industry standards of hydroponic grow mediums. Mineral wools are created by melting rock until if reaches a treacle-like consistency, then drawing out fibres which quickly cool, resulting in a fleece-like fibrous substance. Besides its use in the hydroponics industry, mineral wool has been used as a thermal and acoustic insulator, and also in industrial filters.

Many professional hydroponics companies prefer a rockwool growing medium as its consistency allows for an optimum oxygen/water balance. The texture of this growing medium provides what many see as an ideal balance between three critical properties of any hydroponic substrate: breathability (to allow air in), permeability (for retention of fluid) and a consistency which allows the roots of the plants to anchor themselves firmly and grow freely.

Perlite is a mineral wool created from volcanic rock, and is lighter and less dense than most rockwool. It is good for use with wicking hydroponics systems, where water and nutrients are drawn up through the substrate by capillary action. Experienced enthusiasts and professionals may use perlite as a hydro grow medium, that is, for minimalist systems which use very little substrate and where all variables are directly controlled by the operator. This kind of setup can yield exceptional results with careful monitoring and regulation. Less experienced hobbyists may prefer a denser growing medium, which takes a lot of the hard work out of the process. Another consideration is that perlite dust is harmful, so it must be handled very carefully.

Expanded Clay Pebbles

Clay pebbles are one of our most popular supplementary media due to the unequalled root support they provide. Heating fragments of clay to over one thousand degrees converts it into a light weight, highly porous medium which allows both air and water to pass through and boasts excellent drainage properties. They are totally inert, are easily colonized by beneficial bacteria, and can be washed and reused after each crop.

Coco for Grow Mediums

‘Grow medium coco’ or ‘hydro coco’ are names given to coconut fibre which is used as a grow medium, or as part of mixed grow mediums UK experts recommend for organic hydroponics systems. Once again, water and oxygen capacities are critical and coconut fibre scores excellently in both these areas. Aside from its completely organic nature, ecologically conscious growers may prefer it to rockwool as the latter never fully breaks down after disposal. Coconut fibre, of course is fully compostable. Additionally, high quality hydro coco contains only minimal levels of native nutrients, and is therefore suitable as a grow medium with mixed nutrients solutions in mind.


Not a growing medium, but an all natural additive which can increase the size and number of flowers and fruit, and enhance the taste of your produce. Animal waste -based fertilizers have been common agricultural practice for centuries, so this product, famously made from bat droppings, has a strong heritage at which we should not turn up our noses.

Grow Systems

By breaking a procedure down into its component parts, it is often possible to create a more efficient and controllable process. This is the basic philosophy behind hydroponics. Removing growing plants from their traditional environment – the soil – and bringing them into the controlled environment of a hydroponic laboratory allow the same growth results to be achieved [...]

Read More »

Introducing our dedicated UK Organics website - www.gogroworganics.co.uk

Introducing our new dedicated UK Organic online and retail website - www.gogroworganics.co.ukGo Grow Organics specialises in the provision of organic plant nutrients, natural plant supplements and boosters. We strive to seek out the best possible organic nutrients across the globle, which are kind to the environment and nourishing to your plants. We bring you the [...]

Read More »

Broad Mites & Cyclamen Mites

In this article it will explain exactly what these pests are, how to recognise if you have them and the many guises or symptoms they display, but most important of all, the treatment schedule you will need to follow. So the number one MOST NOT WANTED pests are BROAD or CYCLAMEN MITES.Broad or Cyclamen Mites are the indoor [...]

Read More »

The rise and rise of the dreaded Broad Mite & Cyclamen Mite

In this article it will explain exactly what these pests are, how to recognise if you have them and the many guises or symptoms they display, but most important of all, the treatment schedule you will need to follow. So the number one MOST NOT WANTED pests are BROAD or CYCLAMEN MITES.Broad or Cyclamen Mites are the indoor [...]

Read More »

Need to know series: Neem Oil

This article is all about the neem tree and the benefits people have found when using certain by products like neem oil especially as an insect pesticide. Although the neem tree has been used for centuries, but only until now are some people only now discovering this truly amazing tree’s beneficial and healing properties.Neem trees [...]

Read More »

Basic Vegetative-Health Boost Compost Tea Instructions

This article is all about how to make compost teas and will explain why these teas are fast becoming the best way forward when trying to achieve outstanding organic results for your garden.Great example of a well aerated compost tea.What is a compost tea? Quite simply, it is a liquid, nutritionally rich, well-balanced, organic supplement [...]

Read More »

Charcoal for grow?

This article will explain the benefits of using a great soil amendment like bio char. As a child I was lucky enough to have travelled to many countries around the world and one thing strangely enough that would confuse me, would be the drive from the airport to my Grandmother’s house. You could see [...]

Read More »

Need to know series: Spider Mites

In the indoor grow world over the past couple of months the rise in pesticide sales always rises of course especially around spring and summer. The arrays of questions asked about numerous pests are not only varied but most are geared up to eradication. These need to know articles will be based on the basics [...]

Read More »

22 Top Tips to Help Cool down your indoor Garden

It is clear to see when summer months are just around the corner, especially when you work in a grow shop. Suddenly as early as March you can get a surge of customers coming in and inquiring about ways to cool down their grow rooms. In fact some indoor growers opt to stop growing altogether during the hot summer [...]

Read More »