BGDX by Argent Labs
For the treatment of Bacterial Gill Disease and control of Open Gill Covers.  Powder. 
Dosage is 1 tsp. per 100 gals.
BGDX - 100 gram bottle treats 3300 gallons.  Item #BDGX100....$ 13.95
BGDX - 500 gram bottle treats 16,667 gallons.  Item #BDGX500....$ 29.95