I never thought about the issue of sourcing them there.
Not meaning to butt in.
If you find the guys who are growing flowers/fruits/etc they can tell you where to buy 25kg bags of the stuff. All over the world farmers import stuff from europe,us, now china. About $200 us$ for 6 bags (calcium-nitrate, potassium-nitrate, magnesiium sulphate, mono-potassium phosphate, trace (mix of zinc, boron, molybdenum,etc.) and potassium sulphate). In the ag industry these are standard water-solubles. They have a guaranteed minimum analysis.
Not trying to be a know-it-all just help. It is incredibly easy, cost-effective and produces great results.
I am a techno/science retard in many ways. Even i can use the spreadsheet and scale to do the calculating for the amounts i need to weigh on a scale.
I wish i hadn't had a hard drive crash (no bakeup: yes very dumb) or I could do a brief thread on this outlining the tech.
Absolutely love the thread scooby. Fantastic.
Grow well n safe. pura vida