Where can I buy cal mag in bulk?

[RPM]

I live in West Sussex and would like to buy cal mag in bulk as I have three horses. Post and packing from internet suppliers is nearly as much as the cal mag!

Any ideas?

 

[Dolcé]

Try genuine farm suppliers, we used to get 25k sacks of mag ox for around £7. If you have any sheep farmers near by ask them where they get theirs from.

 

[hayinamanger]

There is probably a large agricultural feed supplier in your area. They will have it for sure.