I saw it on sale locally for $25 for 20 lbs, is it any good?
If it's missing anything, how difficult will it be to complement it?
I can't find calcium mentioned anywhere, does it mean it's missing?
Here's the breakdown:
NPK: 13 - 7 - 20
Mg, S: 1 - 5
N:
Ammonium (NH4) 5.9%
Nitrate(NO3) 7.1%...