My Equilibrium was also hard as a rock. I broke it up with a hammer, but it was still very lumpy so I put it through a sifter, which took quite a long time and wasn't easy.
I stopped using it because it contains a very large amount of potassium - 20% in fact! I dose potassium seperately, so I don't want to be adding it (especially that much) when I raise my gH. It also contains iron and I also dose that seperately.
I switched to Kent Botanica gH+, which is a liquid. It contains only calcium and magnesium.
Some people will use Epsom salts for magnesium and calcium carbonate for calcium, but if my understanding is correct calcium carbonate will raise kH as well and I like to control that seperately.