45 mins? What took you so long
I have Durso's in all 3 of my tanks and have never had them plug up at all. I have occasionally reached in to see if there is anything in or around them but come up empty. As for sound I don't here a thing from them, the hardest part is getting the right size breather hole drilled in to the cap so what I did was drilled a hole big enough for a 3/8" PVC air valve to be able to fine tune it. Just an idea for you to think about.