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Hydrofarm

GROW!T GMC40l - 4mm-16mm Clay Pebbles, Brown, (40 Liter Bag) - Made from 100% Natural Clay, Can be used for Drainage, Decoration, Aquaponics, Hydroponics and Other Gardening Essentials

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Availability: In Stock.
Fulfilled by Amazon
Arrives Nov 26 – Nov 27
Order within 9 hours and 32 minutes
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Size: 40 Liter Bag


Pattern Name: Bag


Features

  • Extremely stable in both pH and EC
  • Made from 100% natural clay
  • Pre-washed to aid in stability
  • Drain freely and do not hold any excess water, providing good oxygen levels around the root
  • Will not float once fully wet

Description

GROW!T horticultural clay pebbles are made from 100% natural clay. They are clean, pH stable, and offer great aeration and drainage in hydroponics, especially in flood and drain, deep water culture, and drip feed systems. Due to their unique structure and ability to cover a large surface area, they offer the ideal environment to foster beneficial bacterial growth around the root zone, leading to naturally healthier plants.GROW!T Clay Pebbles can be used for:•Aeration of growing media - ideal to mix into coco coir or soil to aid aeration •Drainage - will hold water as well as offering great aeration properties and free draining •Decoration - looks great as a top dressing for pots and also helps to prevent evaporation •Hydroponics/hydroculture - used widely in hydroponic growing, they are ideal for flood and drain, deep water culture and drip feed systems •Aquaponics - are also ideal to be used in aquaponic systems

Brand: Hydrofarm


Color: Brown


Product Dimensions: 25"D x 5"W x 18"H


Size: 40 Liter Bag


Special Feature: Drains freely


Brand: Hydrofarm


Color: Brown


Product Dimensions: 25"D x 5"W x 18"H


Size: 40 Liter Bag


Special Feature: Drains freely


Product Care Instructions: Hand Wash


Unit Count: 40.0 Count


Recommended Uses For Product: Gardening


Maximum Weight Recommendation: 2 Grams


Style: Classic


Pattern: Bag


Room Type: Patio Garden


Age Range (Description): Adult


Included Components: Clay Pebbles


Theme: Gardening


Shape: Rectangular


Model Name: GROW!T GMC40l Clay Pebbles, 4mm-16mm, 40 Liters


Arm Style: Armless


Surface Recommendation: Hard Floor


Furniture base movement: Glide


Indoor/Outdoor Usage: Indoor


Fill Material: 100% natural clay pebbles


Leg Style: Sled Base


Reclining Position Count: 1


Tilting: No


Is Customizable: No


Is Foldable: No


UPC: 638104013444


Global Trade Identification Number: 44


Form Factor: Clay Pebbles


Fabric Type: Clay


Manufacturer: PLANT!T


Assembly Instructions Description: None required, ready to use.


Item Weight: 20 pounds


Department: Unisex-Adult


Item model number: GMC40L


Is Discontinued By Manufacturer: No


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Nov 26 – Nov 27

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews

    • The best leca product there is, basically an industry standard
Size: 10 liter Pattern Name: Bag
If you require these, you already know what you need them for. The build quality is excellent. They are simple to setup and easy to use. They do an outstanding job of storing and transporting your water & nutrients. These are the golden standard of leca. Absolutely highly recommended.
Reviewed in the United States on May 26, 2025 by Andy
    • Worked great in my 55gal flood and drain system
Size: 40 Liter Bag Pattern Name: Bag
Review Image by John John
I bought these for my flood and drain set-up. You have to clean these very well as they have a lot of powder from production. As I was cleaning I was worried because they all floated. I made sure all of the water was out of my barrels and filled to the top with rock. I then flooded them and I was very happy because the weight of the pebbles where enough to keep from floating up and over the sides. There is also maybe an inch of dry rock at the top of my system to prevent the growth of alge. They are perfect for my halfbarrel flood and drain. Also if your interested took just about 6 to fill 2 half barrels. Its a lot of money but after digging out my $150 of rock that tested fine with vineger but then the ph started creeping up was not fun either. This pebble is so light and easy on the hands to work with and should withstand for so long I'm happy with the investment. ... show more
Reviewed in the United States on August 4, 2018 by John John
    • Good value for starting semi-hydro
Size: 40 Liter Bag Pattern Name: Bag
Starting my semi-hydro plant journey and bought these. They're not like the perfect orange-y colored balls that you see some people using. These are a regular brown color and are more irregularly shaped, but that's fine for me because I had read it's actually easier to situate your plant in the irregular-shaped leca instead of the perfect balls. For the most part these haven't sunk after soaking them in water (even after soaking for weeks), but I don't think that really matters as far as actually using these for planting because none of the plants I've moved to leca have died and it's been a couple months now. ... show more
Reviewed in the United States on April 21, 2025 by CC
    • Filled 50 4" inch net cups with plenty leftover
Size: 40 Liter Bag Pattern Name: Bag
Review Image by Melissa Patrick Melissa Patrick
Review Image by Melissa Patrick Melissa Patrick
The bag weighed 28lbs on arrival. I filled 50, 4" inch net cups and still have 8 pounds leftover. I was worried there wouldn't be enough but it is plenty for my hydroponic vegetable garden. As far as the quality of the 'pebbles' they seem to be average. For those that are looking for a perfectly uniform round ball appearance, don't get this product. A random sample taken from the bag consists of various shapes, perfectly round being the most rare shape. There are quite a few fragmented and broken pieces mixed through out. As for me, I wasn't concerned at all with looks, only usability, and these seem to work just fine at holding water and creating space for oxygen. I tested their claim of being pH inert and found it to be true. These pebbles did not appear to change the pH of my water. They are gritty however and will need to be washed before use. Overall, happy with the price for the amount and would buy again. update- I soaked the pebbles for 24 hours and they still float on the surface of the water. 24 hours should have been more than sufficient for them to be "fully wet" as the description says. For anyone that needs these to sink to the bottom of water do not get these, they will float. They will work for the purpose of a net cup being about 2/3 submerged in water. Try and submerge the cup in water any deeper and the pebbles will push up out of it. I am still happy with them because I don't need them to be be submerged, only half under the water at most. ... show more
Reviewed in the United States on May 12, 2015 by Melissa Patrick Melissa Patrick
    • perfect item
Size: 40 Liter Bag Pattern Name: Bag
arrived quick and item was perfect. thanks
Reviewed in the United States on July 21, 2025 by Ahhh
    • Clean them thoroughly, works well
Size: 10 liter Pattern Name: Bag
I used this to act as a drainage medium for a reptile vivarium. A lot of people complained about the pieces not being perfect balls. For me, this didn't matter, especially since when I think of "pebbles," I tend to think of imperfect little pieces. The clay pebbles do vary in size, with a marginal amount being tiny enough to slip through a strainer. However, it is quite a large bag and I had plenty leftover. For my purpose, it works quite well. It helps to keep the humidity in the tank without leaving any standing water. I have yet to see any sort of mold or fungus growth. I am quite pleased! Hint for cleaning: I divided the bag into manageable amounts and used an old strainer to rinse them off with the hose until the water runs clear. This a longer process but helps to thoroughly rid yourself of all the dust. I originally tried just throwing everything into a large bin, filling with water, and pouring out the water but I still ended up with dusty water. Do yourself a favor and clean thoroughly the first time around. ... show more
Reviewed in the United States on July 24, 2017 by Lori
    • My favorite LECA
Size: 25 Liter Bag Pattern Name: Bag
I bought this LECA because it was the cheapest I could find for the quantity. As others have mentioned, most of it is not round. If aesthetics are concerning for you, this LECA isn’t for you. I actually think all the variation makes the LECA fit together nicer, and I actually get better results with it. Yes roots stick to it, but roots stick to the round ones too. Yes it’s a little dusty when you get it, but what LECA won’t be? They all rub on each other during shipping. Just rinse it and it’s completely fine. No they do not sink. I don’t know what makes these different than others, but they definitely always float. It doesn’t really bother me, so that’s not a concern. Having said all of that, I’m very happy with it for what it is! It works great and the price is right! ... show more
Reviewed in the United States on June 19, 2020 by Review2Me

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