no way guys that stuff hits the water and pushes it right out of the way. Yes there may be a little mixing at the very end of the af stream but let it run a few seconds longer, OH yeah just run hot and cold I alternate a little. so I get the af about the same time then run it a bit to do the draintraps. I am not trying to tick any body off but I feel blowing alone isn't safe and blowing and af is a bit overkill. I do alot of boats every year and never had a problem. Just needed to get that out in the open. I do however pull the low point drains before and after just in case.