Grodan Gro-Smart Tray Insert

The Grodan Gro-Smart Tray Insert is a double-sided hard plastic insert that organizes Grodan rockwool media inside a standard 10" x 20" propagation flat. One side holds 78 individual 1.5" A-OK Starter plugs or Macroplugs; flip it over and the mesh side supports full sheets of Mini-Blocks and Gro-Blocks. The insert elevates media off the flat floor to prevent sitting water, and the hard plastic construction is dishwasher safe for easy sanitation between propagation cycles.

Grodan Gro-Smart Tray Insert Specifications

Specifications derived from manufacturer product data and canonical product listing.

Why Choose the Grodan Gro-Smart Tray Insert

The Gro-Smart Tray Insert addresses a common problem in rockwool propagation: standard 10" x 20" flats are not designed to hold Grodan media formats in a stable, organized arrangement. This insert solves that by providing a dedicated home for multiple Grodan media types in a single reusable tray.

• Double-sided design covers two media formats. The 78-cell side holds individual 1.5" A-OK Starter plugs or round Macroplugs securely upright. The mesh side accepts full sheets of A-OK plugs, Mini-Blocks, or Gro-Blocks. One tray serves different propagation stages and media configurations without purchasing separate holders.
• Elevates media off the flat floor. The insert keeps rockwool elevated above standing nutrient solution in the flat. This helps prevent over-saturation at the base of plugs and blocks, giving developing roots better access to oxygen.
• Hard plastic construction withstands repeated use. Unlike foam or thin plastic inserts, this durable Dutch tray is built to last multiple grow cycles. The material is non-reactive with standard hydroponic nutrient solutions.
• Dishwasher safe for straightforward sanitation. Between propagation rounds, the tray can be run through a dishwasher for thorough cleaning. This simplifies turnover in high-volume cloning and seeding operations where sanitation is a priority.
• Fits the standard flat you already own. No new infrastructure required. The insert drops directly into any standard 10" x 20" propagation flat, making it a low-friction addition to an existing propagation setup.

Best Uses for the Grodan Gro-Smart Tray Insert

This insert is purpose-built for rockwool-based propagation. It works in any growing environment where Grodan starter media is used — hydroponic, aeroponic, or hybrid systems.

• Seed starting with A-OK Starter plugs. Load the 78-cell side with 1.5" A-OK plugs for germinating seeds. The individual cells keep plugs separate and stable throughout the germination period.
• Clone propagation with Macroplugs. The 78-cell side also accepts round Macroplugs, making this tray usable for cutting propagation as well as seed starting under the same tray format.
• Supporting Mini-Block or Gro-Block sheets. When working with sheet-format Grodan media, flip the tray to the mesh side. The mesh provides support for full sheets of A-OK plugs, Mini-Blocks, or Gro-Blocks while allowing drainage beneath.
• High-volume commercial propagation. In facilities running continuous propagation cycles, the dishwasher-safe construction and durable hard plastic make this tray practical for repeated-use workflows where trays are cleaned and reloaded frequently.
• Pairing with fabric pots in drain-to-waste systems. Propagate cuttings or seedlings in the Gro-Smart tray insert, then transplant rooted plugs or blocks directly into fabric containers for the vegetative phase.

Compatibility

The Grodan Gro-Smart Tray Insert is designed specifically for use with Grodan rockwool media formats and fits within standard 10" x 20" propagation flats.

Compatible Grodan media:

• 1.5" A-OK Starter plugs (78-cell side)
• Round Macroplugs (78-cell side)
• A-OK plug sheets (mesh side)
• Mini-Blocks (mesh side)
• Gro-Blocks (mesh side)

Tray compatibility: Fits any standard 10" x 20" propagation flat. This is the industry-standard flat dimension used in the vast majority of propagation domes, heat mats, and flat benches.

The insert is not designed for use with loose growing media such as perlite, coco, or soil mixes. It is a structural holder for preformed Grodan rockwool units. For growers also working with larger containers, the Smart Pot 20-gallon fabric container is a common next-stage vessel after transplanting from starter media.

The hard plastic material is compatible with standard hydroponic nutrient solutions. No special preparation is needed before first use other than a basic rinse.

Sources & Further Reading