Hmmm.
That looks like it could be either the baking soda or the sea salt or both.
Well, here's what I would do... dump the white stuff back into the water. Nuke in the microwave for 1 minute. Stir until clear. If it's a little bit yellow, nuke again for 20 seconds. The object is to get the sodium bicarbonate ( baking soda) to dissolve completely.
MAKE FAUX SEAWATER - Use for water portion of the lye solution.
1 quart warm water (distilled)
1 Tablespoon sea salt
1 Tablespoon sodium bicarbonate (baking soda)
When I make Faux Seawater, I make 32 oz. at a time and store it in the fridge until I need it. Even if you have no use for the rest of it, sea salt and baking soda aren't all that expensive. My guess is, you'll find other uses for it. For example, warm 4 oz or so in the microwave and gargle/spit for 2 minutes to ease a sore throat.