Crystals in Magnesium

[viperfish]

I purchased Magnesium Chloride and Magnesium Sulfate from Eli and mixed a gallon jug about a month ago. I grabbed the jug to fill my dosing container tonight and I noticed a bunch of crystals had formed in the solution. I tried shaking it up hoping to dissolve the crystals but it's darn near impossible. I have the jug soaking in warm water now, hopefully the heat will help dissolve them. Has anyone experienced this?