When the nutrients and salts start to congeal, minor deficiencies can start to occur, and watch ingoing ph on feeding day. I just shake the crap out of it till it sounds like there are more chunks than liquid. If I could afford to buy fresh every 6 months, I would. But I have never really had a major issue in using somewhat chunky FF nutes. When the nutes start getting old, check for ph swings after mixing and watch runoff ph a tad closer.

Keep in mind I use Soil Syrup (humic acid) after every monthly mini flush, (1:1 ph'd water to pot volume) and I have drastically cut back on the Big Bloom through the entire grow, (1 tsp:gallon, twice a week) and replaced it with molasses, (1 tsp:gallon, twice per week) which also effectively and cheaply replaces the Botanicare Sweet and CalMag I used to use in flower.