Grodan A-OK Starter Plugs 1.5in PRO Case | 30 Sheets, 2,940 Plugs

What a Case of Grodan PRO A-OK Starter Plugs Holds

Thirty sheets, ninety eight plugs on each one, so 2,940 plugs in the carton. Grodan call this format 36/40, and their own part list gives the plug as 1.4 x 1.4 x 1.6 in rather than the 1.5 in the name implies. That difference is not a rounding error you can ignore, because 98 plugs land as a seven by fourteen grid. Seven plugs at 1.4 in come to 9.8 in across and fourteen come to 19.6 in long. That is exactly why a sheet drops into a standard 10 by 20 flat. At a true 1.5 in the same grid would overhang the tray. The material is stone wool, spun from molten rock and compressed into a fibrous block that holds air and water at the same time. Part number 293824 is specifically the unwrapped version, with the sheets stacked loose inside the carton. Grodan also list 298490 as the shrink wrapped carton and 343295 as pre-cut plugs loose in a box. Unwrapped is the lowest cost way to move this many plugs. It is what a propagation room takes when sheets get broken down the same day they arrive. There is no printed instruction label on a loose sheet, because that label lives on the shrink wrap.

Conditioning a Stone Wool Starter Plug Before Anything Goes In

Stone wool leaves the factory alkaline, and that is the one step people skip. Soak the sheet in pH adjusted water and let it drain before a seed or a cutting touches it. Skip that and the first week of the crop fights water chemistry instead of growing roots. Grodan publish no conditioning pH or EC figure for this plug, so match whatever your base feed targets rather than guessing a number. The plug profile tapers, which keeps roots inside their own cell and lets a sheet pull apart cleanly when you block on. That matters at scale, because a tangled sheet costs more in torn roots than the plugs are worth. Irrigate little and often while the root is still in the plug. A saturated block of stone wool holds far more water than a young root can use. Most rooms run these for a week to two weeks and then transplant into a larger block. A full carton is a commitment: 2,940 plugs will not keep indefinitely once the sheets are opened and handled. Anyone sowing a tray at a time wants the shrink wrapped version or a single sheet, which is a separate listing here.

Key Features

• 2,940 plugs per case: Thirty sheets of 98, stacked loose in the carton as supplied.
• Unwrapped format: Part number 293824, which is the version without shrink wrap.
• 36/40 plug format: Grodan list the real size as 1.4 x 1.4 x 1.6 in, not 1.5 in.
• Seven by fourteen grid: Why a sheet fits a standard 10 by 20 flat without trimming.
• Stone wool: Spun from molten rock, so it holds air and water together.
• Tapered cell: Roots stay in their own plug and sheets separate cleanly.
• Condition before sowing: Soak in pH adjusted water, because stone wool is alkaline as made.
• Blocks on: Moves into a larger stone wool block after a week or two.

Technical Specifications