Which Growing Medium is Best?

There is really no growing medium that can be labeled as “best”. Each particular medium has its own advantages and disadvantages (please see descriptions of each inpidual media below). However, there are many different factors that will determine which type of media is right for you.

1. What type of hydroponics system will you be growing in?

If you are planning on growing your plants in a hydroponic system it is important that you chose a media which will give you greatest opportunities for success. *Never use potting soil or dirt in a hydroponics system*

Ebb and Flow (Flood and Drain) Systems

The Ebb and Flow system can be used with just about any media. Most growers will use either Rockwool, Coco or Ready Gro. If you choose one of these mediums it is wise to avoid over watering by spacing out your watering cycles by at least 3 hours since both of these media tend to retain a lot of water. If you choose to use Hydroton Rock or Perlite you will need to prevent your media from drying out, therefore more frequent watering is necessary.

Top Feed/Drip Systems

The Top Feed/Drip Systems can also be used with most media yet once again most growers will prefer to use Rockwool, Coco or Ready Gro. Most Top Feed systems are stake based, meaning that a drip line is connected to a drip stake and the drip stake is plunged into the media. Because of these stakes most growers will use rockwool and coco because it is easier to insert the stake into these media. As with an Ebb and Flow System, it is very important to avoid over watering. Certain Top Feed/Drip Systems (i.e. The Waterfarm by General Hydroponics) feature a constantly dripping “ring” or apparatus that continually waters the media. In cases such as these the Hydroton Rocks are the best media to work with since they do not retain a lot of water. Perlite is not recommended in this case since Perlite tends to clog the drainage fixtures of these particular Drip Systems.

Aeroponic Systems

Aeroponic systems usually require very little media. Due to the constant misting of the roots most growers will use small Rockwool cubes for their seedlings/clones and then transplant them into Hydroton Rocks once they are ready to be placed into the Aeroponic system. The Hydroton Rocks allow for the Aeroponic misters to spray in extremely short, but frequent intervals, without resulting in over watering.

Nutrient Film Technique (NFT) Gully Systems

Nutrient Film Technique/Gully Systems also require very little media. Most growers will simply start their seedlings or clones in small rockwool cubes, ranging anywhere from 1” to 3” depending on your particular system, and then place these cubes into the system. Because NFT systems feature channels of constantly re-circulating nutrient solutions, the roots of the plants tend to grow down from their small starting cubes into the various channels making any additional media unnecessary.

2. Are you hand watering?

If you plan on hand watering your plants then there are certain media that are more suited for this application than others.


A good, healthy, nutritious soil is an excellent choice for a grower that will be hand watering his/her plants. We recommend choosing Fox Farm’s Ocean Forest Soil because of its high nutritional value and general superiority to other soils (please see description below). If you do choose to use soil, it is very important that you do not over water. You should not need to water more than a 3-4 times a week, and generally you will not need to apply a nutrient solution more than once a week. When watering your plants it is important that you experience at least 10% run off out of the bottom of your containers. This will help to avoid nutrient buildup.


Coco is another good choice for hand watering growers. In order to determine when it is necessary to water your Coco again you should grab an inch or so of media off the top and squeeze. If little to no water comes out, it is time to water again. For plants that require aggressive feedings it is possible to apply a nutrient solution with every watering. For plants that do not require an increased amount of feedings you can apply your nutrient solution at every 3rd watering. If you decide to apply a solution with every watering it is necessary to apply a flushing agent at least once a week to avoid an excessive build up of salts in the media. As with soil, you will want to make sure that you achieve at least a 10% run off at ever watering.

Ready Gro

Ready Gro can also be used in hand watering situations. Because Ready Gro is essentially Coco that has been cut with Perlite and a few other ingredients it tends to dry out a little faster than straight Coco. This may lead to a need for increased waterings in order to keep your plants from drying out. As with Coco, you will want to check the moisture level of the Ready Gro in order to determine if it is necessary to water. Once again, aggressive growers may apply nutrient solutions with every watering, but it is also possible to apply solutions at every other watering or every 3rd watering. A run off of at least 10% is necessary.


Rockwool can be used in hand watering situations but generally is not chosen. Rockwool blocks usually do not provide the proper environment for hand watering and may begin to break down. A grower can place rockwool blocks within growing containers but it would be wise to use another, “looser” media such as Coco or Ready Gro to fill in the gaps. This prevents the roots from being exposed if they grow out of the cubes. If you chose to use Rockwool cubes by themselves do not remove the paper around the large cube that your smaller cube is sitting in. This will help to maintain the integrity of the cube. If you do place the Rockwool within another media like Coco or Ready Gro then remove the paper, this allows the roots to grow horizontally as well as vertically. As with Coco, you will want to check the moisture level of the Rockwool in order to determine if it is necessary to water. Once again, aggressive growers may apply nutrient solutions with every watering, but it is also possible to apply solutions at every other watering or every 3rd watering. A run off of at least 10% is necessary. Do not allow your Rockwool to sit in standing water.

Hydroton Rocks/Perlite

If you are hand watering we do not recommend that you use Hydroton Rocks or Perlite as you primary media. Both media tend to dry out too quickly and will require too much watering throughout the day. Hydroton Rocks can be used with either Soil or Coco to improve drainage by lining the bottom of your growing containers with about an inch or so of Rocks. Perlite can also be used to improve drainage by mixing it with Coco at around a rate of about 60% Coco to 40% Perlite. Do not mix Canna Coco with any Perlite.

What mediums are available for growing plants?

Potting Soil

Potting soil is favored by beginners and organic growers. There are many types of potting soil that is available to the grower. For best results and healthiest plants always select the best growing medium available. At Better Grow Hydro, we have selected Fox Farm Ocean Forest potting soil as it is the best potting soil available. Fox Farm Ocean Forest soil is 100% organic, with no vermiculite or any other artificial additives. Ocean Forest soil is soft and friable and has a consistent texture. Other cheaper brands will have large amounts of perlite and/or vermiculite and other synthetic additives; the texture is usually inconsistent and normally lumpy. These cheaper brands will also use chemical nutrients in there soil mixes.

Plants that are grown in containers with potting soil are always hand watered and usually fed once a week. Both chemical and organic nutrients can be used with potting soil. If chemical nutrients are used be careful not to over feed your plants. Balance your pH to 6.3 - 6.8 before feeding or watering your plants. Adding mycorrhizae to your soil before planting will benefit your plant roots system, reduce root rot and increase your plants nutrient uptake from the soil.


Perlite is a great medium to use in hydroponics; however, it is extremely light and will float. If using perlite in and Ebb & Flow system never flood your tray to the top, especially when your plants are still young – this will cause your growing pots to topple over. Perlite is hardly ever used on its own; it is normally used in mixes with coir (coco), vermiculite or potting soil. Perlite is used to help aerate other growing mediums and aid in drainage.

Ready Gro

This is a coir/coco and perlite mixture that is ready to use and contains several ingredients that are beneficial for both protecting and enhancing the growth of plants and their root systems. There are two formulations available: Aeration and Moisture formulas. The aeration formula has more perlite than coco and the moisture formula has more coco than perlite. Both of these mixes are suitable for ebb & flow and drip hydroponic systems. Both mixes contain: Coco Fiber, Perlite, Pumice Stone, Earthworm castings, Agrimineral 72TM, Acadian Seaweed Meal, Leonardite Ore (Natural Humates), Pure Blend Original, Root Shield TM (trichoderma), Ascend TM (mycohrrizal fungi), and Guardian TM (Organic Root Inocculant).

Hydroton Rocks / Grow Rocks

Also known as clay rocks, this medium is excellent for use in ebb & flow, drip and aeroponic systems. Rocks drain very fast and will dry out very quickly if not regularly watered. The timing of your hydroponic system’s watering cycle must be frequent so that the rocks don’t dry out. Rocks can be easily flushed of any chemical nutrient build up. Rock is often used to help other growing mediums with drainage by placing an inch of rocks at the bottom of the pot.


This growing medium is a product of coconut husks. It is rapidly replacing rockwool as the most widely used growing medium among commercial hydroponic growers. Coco is available from countries such as Sri-Lanka, India and Mexico. Growers should be careful with their selection of coco as not all coco is of the same quality. Many of the cheaper brands will have poor quality coco, coco that is high in sea salt and even contain a lot of beach sand. We have selected the two best brands of coco available to growers: Canna Coco and Botanicare. The Canna coco is pre washed and disinfected using steam. Canna coco is also inoculated with trichoderma which is a fungus that colonizes the root structure. Trichoderma feeds on fungi in the growing medium that causes root rot and it also helps stimulate the plants health system. Canna Coco is available in 50 liter bags and growing bags and is ready to use. The Botanicare coco is also pre-washed and is available in compressed bricks, growing bags, bulk bags, etc.


BetterGrow Hydro offers Grodan brand rockwool. The Grodan brand has been available to growers for decades and is extensively used in commercial hydroponics. It is well regarded as the best rockwool in the world. Rockwool is made from molten basalt and limestone rock. Rockwool is a sterile inert medium that is perfect for hobby hydroponics growers. Growers should always pre-soak their rockwool using a rockwool soaking product or simply soak in water with a pH of 5 overnight. This will help stabilize the pH of the rockwool, which is naturally very high. Grodan rockwool is available in many sizes from 1” cubes to 6” blocks, as well as slabs and granulate.

Do I need to pre-treat my rockwool?

Yes, Rockwool must be pre treated before use because it has a very high pH. In order to treat Rockwool it is necessary to soak it overnight in water with a pH balance of 5. You can also treat Rockwool with agents like Rockwool Soak which not only lowers its pH, but adds beneficial nutrients.