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Redrock Rockwool Cube – 4' x 4' PRO Stone Wool Starter Block with 42/40 Hole | Rockwool for Hydroponics and Indoor Growing | 6 Pack + Twin Canaries Chart

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$16.99

$ 7 .99 $7.99

In Stock

About this item

  • Rockwool Cube for Hydroponics & Propagation – This 4” x 4” stone wool cube is engineered for early-stage growth and propagation in hydroponic systems, perfect for leafy greens, herbs, and fruiting crops.
  • Pre-Formed 42/40 Planting Hole – Each block includes a standard 42/40 mm hole designed for clean and easy transplanting of starter plugs or cuttings.
  • Inert Stone Wool Composition – Manufactured from dense, U.S.-sourced rock wool for a sterile, soil-free environment that supports consistent moisture and air balance.
  • Efficient Moisture Retention – These rock wool planting cubes retain water evenly while allowing proper dry-back and air exchange, helping maintain healthy root zone conditions.
  • Compatible with All Major Systems – Ideal for use in ebb & flow, drip irrigation, and other hydroponic setups—trusted by greenhouse operators, indoor growers, and commercial cultivators.



Product Description

redrock rockwool for hydroponics
redrock rockwool for hydroponics
redrock rockwool for hydroponics
redrock rockwool for hydroponics
redrock rockwool for hydroponics
redrock rockwool for hydroponics
redrock rockwool for hydroponics

Gazoo
Reviewed in the United States on March 14, 2025
No complaints
Victoria Reese
Reviewed in the United States on August 22, 2024
Worked as described
Jessica
Reviewed in the United States on March 30, 2024
A+
ronsandy
Reviewed in the United States on October 31, 2024
Fast service great product
mad max
Reviewed in the United States on June 4, 2023
Works well for hydroponic setups. Roots moved through within 3-4 days.
amanda
Reviewed in the United States on September 28, 2022
I've been a grodan user for 15 years. They wouldn't come as fast so I tried these. Far superior product in every way. Takes in water much easier and there aren't any hard spots in them like I've been seeing in other cubes
Gideon Weyl
Reviewed in the United States on June 1, 2022
Planted five seeds directly in holes of presoaked cubes and placed into humidity tray under minimum amount of light. Within two days all five seeds had germinated, sprouted and already grown into robust healthy seedlings an and transferred seedlings in rockwool into soiled pots.Two months later... Unbelievably healthy plants.
Jeffrey Myers
Reviewed in the United States on November 3, 2022
Everything works fine with these just wish they were a little deeper holes and I wouldn’t have to dig them out to put the other 1 inch cubes in.
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