I had a set installed when I ordered my boat this year, and have used them through about 6 tournaments so far. I can say that they change the amount of foam and odor in the levee wells. water looks much cleaner and fresher. Is it all due to the vents, No, but for no more than they cost, it is worth it to me. Im a believer, and will install them on future boats. By the way, the finished installation is very clean. You really forget they are in place. Mike Whitten