How to Make It
In a large glass bowl, dissolve the salt in the water. Add the cabbage, carrot and daikon. Cover with a plate. Set a sheet of plastic wrap on the plate and top with a heavy pot to keep the vegetables submerged. Let stand at room temperature until the vegetables are covered with 1 inch of liquid, 2 hours.
Pour off the liquid and reserve it. Lightly rinse the vegetables in a colander, then drain. Transfer the vegetables to a clean large bowl. Add the garlic, scallions, ginger, red chiles and chile powder and toss well.
Tightly pack the vegetables into a wide-mouthed 1-quart jar; add enough of the reserved liquid to cover. Using a chopstick, poke out any air bubbles. Press a small bowl on top of the vegetables to keep them submerged. Cover loosely. Let stand in a cool place for 5 days, adding more reserved liquid as needed to keep the vegetables covered.
Discard any liquid and seal the jar. Refrigerate the kimchi for up to 1 month.