Updated for 2026 — This article has been reviewed and updated with the latest recommendations.
7 Best Growstones for Cannabis Growers in 2026
Growstones are a hydroponic growing medium made from recycled glass that has been foamed into lightweight, porous aggregates. They serve the same purpose as clay pebbles (hydroton) or perlite but with some distinct advantages: better aeration, higher water retention, and a sustainable manufacturing process. Here are the best growstone and similar aggregate options for cannabis growers in 2026.
1.
Growstone GS-1 Hydroponic Substrate
Price: $28 (1.5 cubic feet)
The GS-1 is the standard Growstone product designed specifically for hydroponic systems. The porous structure holds air and water simultaneously, providing roots with both the oxygen and moisture they need. Each piece is irregularly shaped, which creates air pockets between stones that promote root growth. The pH is neutral out of the bag, so you do not need to soak and rinse extensively like you do with some clay pebbles.
Works in drip systems, flood and drain, Dutch buckets, and DWC as a top-dress. This is the default choice for growers who want to try growstones for the first time.
2. Growstone GS-2 Mix This!
Price: $22 (1.5 cubic feet)
GS-2 is a smaller aggregate designed to be mixed into soil or coco coir rather than used as a standalone medium.
Adding 15-25% GS-2 to your potting mix dramatically improves aeration and drainage, which prevents the waterlogged conditions that cause root rot. The smaller particle size integrates evenly throughout the soil, unlike large perlite chunks that tend to float to the top after watering. If you grow in soil or coco and want to improve root zone conditions without switching to full hydro, GS-2 is the most effective soil amendment in this category.
3.
Hydroton Original Clay Pebbles (LECA)
Price: $30 (25 liters)
Hydroton clay pebbles are the traditional hydroponic aggregate and still the most widely used. The round, uniform shape allows for excellent drainage and air circulation. They are pH neutral after rinsing, reusable for multiple grows, and basically indestructible. Where they fall short compared to growstones is in water retention, clay pebbles drain almost completely between watering cycles, which means more frequent irrigation.
But for flood and drain systems where that fast drainage is a feature, Hydroton remains the industry standard.
4. Mother Earth Hydroton (Original)
Price: $26 (25 liters)
Mother Earth Hydroton is the same expanded clay aggregate as the original Hydroton but distributed under a different brand since the original manufacturer changed hands.
The quality is identical: round, lightweight, pH stable, and reusable. The 25-liter bag fills a few 5-gallon buckets for a DWC or Dutch bucket setup. Pre-rinse to remove dust, soak for 24 hours before use, and these are ready to go. Reliable and proven over decades of hydroponic growing.
5.
Viagrow Growstones Hydroponic Growing Media
Price: $25 (1 cubic foot)
Viagrow packages growstones in convenient sizes for home growers. The aggregate is similar to the Growstone GS-1 in composition and performance, made from recycled glass with a porous structure that balances air and water. The 1 cubic foot bag is a good trial size if you want to test growstones in one or two containers before committing to a larger quantity.
The price per volume is slightly higher than buying in bulk, but the smaller bag reduces waste if you decide the medium is not for you.
6. Growstone GS-4 Soil Aerator
Price: $20 (9 liters)
GS-4 is the coarsest Growstone product, designed as a bottom layer in containers to improve drainage below the root zone. Place a 1-2 inch layer of GS-4 at the bottom of your pot before filling with soil or coco coir, and it creates a drainage reservoir that prevents water from pooling at the bottom where roots sit. This is particularly useful in fabric pots and plastic containers without great drainage. A simple upgrade that prevents one of the most common problems in container growing.
7. Hydro Crunch Expanded Clay Pebbles
Price: $20 (10 liters)
Hydro Crunch is a budget-friendly expanded clay option that works well for growers who need to fill a lot of containers without spending a fortune. The pellets are slightly less uniform than Hydroton, with more variation in size and shape, but functionally they perform the same way. Rinse and soak before use to remove the fine dust that comes in every bag of clay pebbles. For growers running large setups where aggregate cost adds up, Hydro Crunch brings the price down without a meaningful performance sacrifice.
Growstones vs. Clay Pebbles
Growstones hold about 30% more water than clay pebbles, which means longer intervals between watering and less stress on roots during dry periods. They also provide more surface area for beneficial microbes to colonize. Clay pebbles drain faster, which some growers prefer in flood and drain systems. Both are reusable and pH neutral. The best choice depends on your system type and how hands-on you want to be with irrigation scheduling. For most home growers, growstones are the more forgiving option.
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