Acurel-Ammonia Away Green. Laboratory proven to be two times more effective than competing products at removing ammonia (the number one killer of tropical fish). This super-effective green zeolite is superior to standard zeolite, making it the best way to rid aquariums and ponds of ammonia. Ammonia Away Green creates a healthy enviroment for fish, minimizing foul odors and cloudy water conditions. This 4.375x5x4.375 inch container holds 36.5 oz filter pebbles. Imported.