Instant Ocean mixing

[Bartman]

I have the same problem but I'm pretty sure I know what started it. I did not have the problem until I didn't seal the lid after a water change one week. The lid was loose for 2-3 weeks and when I went to use it the salt had hardened into clumps I had to break up to use. I have had white precipitate ever since then. The bucket is almost empty now and no ill effects on either of my tanks using the salt.

The precipitate either slowly disappears or mixes with my sand. I'm not sure.