Hello, I'm confident I can offer the following:
1x 1.8 kg Tropic marine pro Special mineral (HMA indicates 1kg would be enough for 1.5 - 2 years, so we're talking almost 3.5-4 years of salt for a 115 gal)
I'm happy to provide this product to my RS friends at cost - since I'll be learning about balling along with all of you. I think right now about $75 but that might come down once I get solid shipping and euro to dollar numbers.
If your interested in ordering some, let me know. I might also consider splitting these containers up, since a 4 years supply seems a bit excessive.