I ran across ZeoMag which is Dolomite at AquariumSpecialty.com for $23.50 per kg:
http://www.aquariumspecialty.com/catalog/product_info.php?products_id=847">http://www.aquariumspecialty.com/catalog/product_info.php?products_id=847</a>
They also carry reactor media in the larger size (not as cheap as the GenX though):
[IMG]http://www.aquariumspecialty.com/catalog/product_info.php?products_id=884">http://www.aquariumspecialty.com/catalog/product_info.php?products_id=884</a>
Shipping was very reasonable.
http://www.aquariumspecialty.com/catalog/product_info.php?products_id=847">http://www.aquariumspecialty.com/catalog/product_info.php?products_id=847</a>
They also carry reactor media in the larger size (not as cheap as the GenX though):
[IMG]http://www.aquariumspecialty.com/catalog/product_info.php?products_id=884">http://www.aquariumspecialty.com/catalog/product_info.php?products_id=884</a>
Shipping was very reasonable.