I have received my order of Bti. There is discrepancy of how much and how often to apply. This particular container is labeled for mosquitoes, so they give information on how much to put in a pond. (2.4 millileters per 1,000 gallons.) I had emailed the distributor and got two different answers. One said nine drops per 150 gallons. The second said 20 drops per gallon. (A HUGE difference.) At this time, I am following the instructions per the University of Arizona Coop Extension recommendations of six drops per gallon. She said to get a pump up sprayer and spray underneath plants where it is moist and any area where it is moist, which is where gnats, flies, and mosquitoes lay their eggs. Supposedly this stuff kills off the larvae. She said to reapply it every two weeks. I almost hate asking the distributor for anymore advice since I got such a stark difference in amounts earlier. I am hoping to find out who has answers, like how many drops per gallon and does it lose effectiveness when it dries out (meaning to reapply it more often than every two weeks here in hot Tucson, Arizona.) I went ahead and applied my first dose Saturday. I am waiting for more response from the distributor. Until then, hopefully this product will work.