Not sure about the sales gimmicks you mention.Would it stand to reason that you would want the most turnover with your 1.5 cfm pump out of a diffuser. If one diffuser turns X and another one XX and another one yet turns XXX at the same CFM wouldnt turnover rates which effect what % satuation of DO (aeration) and temperture you will be able to keep your water at be of value.Or spend the $$ on the DO and temp monitoring equipment and you will know when to run and when not to.Are you looking to keep a very high % saturation of DO to maximize on aerobic bacteria throughout the entire pond or enough aeration to keep fish alive. The term "aeration" is very broad term, This is why sizing a system entails the ponds history,water source fish type fish population,nutrient load, fishing and or recreational,current goals etc. Often the biggest variable from pond to pond is the ability of the aeration system to provide the correct turnover times throughout the entire body of water. Good Luck
