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Deposits in cone 6 glaze bucket

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Has anyone experienced getting hard, round deposits at the bottom of glaze bucket?  All my glazes are cone 6, and I use epsom salt saturate in all my glazes.  These are hard round beads that actually seem to embed in the bottom of the glaze bucket.  I can't really find any cause and it doesn't occur in all my glazes.  I think it's mostly in glazes that are a base glaze plus a Mason stain.  Any thoughts would be helpful on what it is or how to fix.  Thanks!

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There’s actually a number of things that could be causing it. Do your glazes contain lithium? Or a boron/calcium combination? If yes to either of those two things, has your bucket been stored below about 15*C? Lithium will precipitate out, and calcium/boron crystals form when your bucket gets too cold. The calcium boron ones can be pretty stubborn, and I’ve noticed they can cling to the bottom of a bucket that’s sat for a few months. 

As a side note, I found using a saturated epsom salt solution rather than the dry stuff seems to keep it from recrystallizing. I don’t know if it’s because you wind up using less, or what. 

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I get those little hard balls in my glazes all the time. Could be epsom, could be boron. They don't seem to have any effect on the glaze, though. Whenever I top off a bucket I sieve them out and carry on. I also get thin flakes precipitating out on the side of my buckets with some glazes. I believe those flakes are boron or sodium (could be either based on my glaze recipes), because if they land on the surface of a pot they leave a little extra-glossy spot there after firing.

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