MC / greenleaf itself recommends mixing ahead by at least 12hrs if you experience precipitate. i'm fairly certain jack's does as well.
whatever is left on the bucket walls doesn't seem to result in any growing issues.
WHAT IS MC? maybe you should use a different ferts supplier like general hydroponics ready available on amazon
from time to time , gh say the micro nutes should be added 1st as the hardest to go into solution.. 30 secs for me
with a hand stir.. i also ph down my water from 7.2 to 6.2 area.. helps nutes go into solution..
if you have precipitation then some nutes are not going into solution and u dont know what your feeding exactly
yeah i would switch companys.. hey i got some remo nutes starter pack?