I am in no way bashing this product
, I actually love the product, it just seems to be a tad lacking in the magnet department.
I do a lot of lagers and need big starters, which seems to be to much for this stir plate. I realize it wasn't designed for gallon starters, but it is capable of doing them. I simple got bigger rare earth magnets and stuck them over the old ones, no gluing, no fuss.
They are actually a little adjustable so you can get a nice smooth spin. Not only does it create more pull, but it gets the magnets closer to the lid. I couldn't get it to pull the stir bar to the center on 3.5 quarts of water. I used another magnet to center the stir bar then placed it on the plate, it would just dimple the top of the water.
The new magnets would pull a vortex halfway down the jar, a big improvment, to a very good product.