Does anyone that you know of make a "plug popper" for the 128 cell tray?
Not that we know of, but we are working on it ourselves... unfortunately we don't have an ETA for that one yet.
Your trays of 200 and 128 both have exact same dimensions. So that is not possible. What's the difference?
Our 200 cell tray has ¾” squares and our 128 seed starter tray has 1" squares.
How many come in a pack?
There is 1 tray per pack. So a 5 pack of the 128 Cell Seed Trays is 5 Trays.
What's the best tool for popping the plugs out? Every nailhead (I've tried) small enough to fit through the drain hole stabs right through the plug.
We typically just pinch them out. You can also give the bottom of the cell a squeeze. If you are still having trouble you can use a widger or a popsicle stick. Any of these methods and they should pop out.