All the ads say everybody needs it. I've received at least three solicitations the past week alone. Mostly they say the bacterial will reduce muck, clear the water and reduce or eliminate algae. I think I kinda understand the basics of bacteria in the nitrogen cycle from my experience with aquariums: Bacteria "eats" the organic waste (plant material, fish food, excrement, etc") and converts it into nitrites then nitrates which plants then take up and use like fertilizer. Ammonia that's poisonous to fish gets processed somewhere with the organic waste too. Nobody wants a pond full of fish poop so I see how this is good. There's also a couple of different types of bacteria: aerobic, where oxygen is present and anaerobic where's there's little or no oxygen. I'm pretty sure the places where anaerobic bacteria grows is in that stinky black mud in stagnant water that make you smell like you've been wading in a septic tank rather than a fishing hole. I'm not sure I could tell where aerobic bacteria is but my guess is it's probably where the water is moving around and aerated. Back to the ads: Clearing the water. Although clear water is better for swimming, everything I've read says you want green water, green from planktonic algae, dense enough that visability is reduced to around 16". Planktonic algae produces oxygen, feeds zooplankton (and on up the foodchain), and helps shade deeper water to help prevent submerged weeds from growing. So if you're trying to grow fish wouldn't clear water be bad? Reduce or eliminate algae: Filamentous algae, the fuzzy green stuff I usually start seeing around this time of year, grows off of the same nutrients as the planktonic if I'm understanding correctly so wouldn't adding more bacteria speed up the decomposition, release nitrates faster and fuel more algae growth? I'm aerating my pond and have noticed less filamentous algae in the spring and my water has cleared some too. I was assuming that the clearing was because the planktonic algae near the surface it was being mixed throughout the water column rather than in a dense layer near the surface. I've found filamentous algae very easy to control with spot treatments of copper sulfate liquid or tilapia so it's not a problem really. What kind of bacteria is in the container? Is it anaerobic, aerobic or both? Would you use one type in an aerated pond and another type in a non-aerated pond? So how will beneficial bacteria help me grow bigger fish? Is it practical for a 1/2 to 1 acre pond? Is it expensive? How often does it need applied? How long does it take to see results? Anybody on here using it?