ADA stands for Aquatic Design Amano. That group sells a very nice looking glass one, but Amano doesn't use it. You are closer to Hong Kong than we are so the ebay one is your best bet: eBay Store - T 1Brian-Aquarium Plants Supplies: CO2 Diffuser, Water Conditioner, Fertilizerlaka;14112 said:Yes i agree Even LaMotte admit this. I live in Australia. Where can i purchase a drop checker from? What does ADA stand for?