How to Choose the Best Rockwool for Your Hydroponic?

Nov. 15, 2021

How to Choose the Best Rockwool for Your Hydroponic?

Hydroponics is a method of cultivating plants without soil. Hydroponics uses an inert medium of mineral nutrients suspended in water, so the plant does not need to extract minerals from the soil to survive. There are many advantages to using hydroponics, including faster growth rates than conventional methods, energy conservation, and the ability to grow on urban rooftops or balconies with little space.

Related: Is Conventional Farming Sustainable or Should We Need Hydroponics?

What Is Rockwool’s Contribution to Hydroponics?

Rockwool is a hydroponic growing medium. Rockwool is a great material that has been used for years to grow plants with hydroponics. It is porous, which means it will absorb water and dissolve nutrients. If you’re looking for an easy way to start growing your food at home, Rockwool may be the solution for you!

The hydroponics technique of Rockwool relies on the hydroponic plant roots being submerged in water for aeration and nutrients to be dissolved into the feed water so that the plant can absorb them through its root system, making their roots happy and healthy.

Hydroponic plants are grown using hydroponics without soil, so they rely on inert hydroponic media like Rockwools or expanded clay pebbles for support and structurally-sound anchoring.

Related: 12 Top Benefits of Rockwool in Hydroponic Systems

Types of Hydroponics Rockwool

Rockwool comes in many different forms, but the most common are cubes and slabs. It’s time to know more about them.

1. Cube Rockwool

Cube Rockwool is the most common type of hydroponic growing medium. It’s cube-shaped and made up of tiny little fibers that are braided together. The manufacturer first soaks this braided block in a nutrient solution to form the Rockwool cubes you can buy in hydroponics stores.

Cube Rockwool is very easy to use. Simply soak the cubes in a nutrient solution and place them in your hydroponic system’s reservoir. The blocks will absorb water and dissolve the nutrients into the solution, after which they simply need to be topped off with more water periodically for a continuous supply of nutrients.

Rockwool cubes are inexpensive and easy to handle. Still, the downside is that you need to be careful not to damage them when transplanting plants from one system to another or from root tubs into Rockwool cubes.

2. Slab Rockwool

Slab Rockwool is a relatively new type of Rockwool made specifically for hydroponic growing. The Rockwool is manufactured in large sheets that are then cut into slabs weighing about 1 lb each.

Slabs can be used just like cubes, but they’re much easier to handle when transplanting your plants because they’re larger than cubes. They also provide more surface area for roots to grow, which is beneficial if you plan to transplant several times during the vegetative stage.

This type of Rockwool also provides more oxygenation than cubes do because more air can reach the center of the Rockwool. Slabs are made of thick strands that make them durable and easy to handle without damaging roots or stems.

Slab Rockwool is more expensive than cubes, but it’s a good choice for those looking to save time and money as plants mature.

Slab or cube-type Rockwools may be made as light or heavy and are available in their range of densities.

The choice of density is determined by the application for which they are to be used.

Lightweight Rockwools may be used for seed germination or in systems where plant weight is not a significant factor.

Heavyweight Rockwools are used in situations where the weight of the plant must be supported (e.g., grapevines) or when it is desirable to hold water against gravity (e.g., hydroponics behind glass).

3. Granulated Rockwool

Granulated Rockwool can be used for hydroponics and also as a soil amendment. It needs frequent replacing. Granulated Rockwool can be used alone in pots or as an amendment to organic-based mixes.

Granulated Rockwool can be hydrated with water when hydroponics is concerned and then added to a hydroponics reservoir. Using granulated Rockwool in hydroponic systems must be hydrated first because dry Rockwool could burn plant roots.

What Type of Rockwool Would You Purchase?

The type of Rockwool you choose will depend on your needs. This is because hydroponics relies on many different variables, such as the size and shape of your hydroponic system or whether it’s indoor or outdoor.

The first thing to consider when purchasing hydroponic Rockwool is what type of system you have, do you use a hydroponically-grown plant in an indoor environment? Or are they grown outdoors?

If you’re new to hydroponics and want to get an idea of how it all works, try using cubes. If indoors, cubes will work well for most plants. At the same time, slabs might not provide enough support if there’s no transplanting during vegetative stages.

If you’re looking to save time and money and don’t plan on transplanting during the vegetative stage, then slabs may be a good option for you. Lightweight means the wools are easier to handle, while heavyweight offers more support for plants. Thick strands make handling easier without damaging roots or stems.

Rockwool cubes and slabs work great for hydroponic tomatoes and lettuce, and strawberries. If you like to try different things and experiment, go ahead and get any type.

Thank you for reading!

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