“second one of these I've bought - quality seems variable. they're mostly pretty quiet and flow is ok but not amazing - really fragile connectors too, previous one had one tube connector break right off. this one had a problem with thread length internally, when pump under full load was making quite a lot of noise. opened it up and found screw threads knocking together. filed 1mm excess off threads and now runs silent. ok for price but there's probably better out there.”
“Going by the info I honestly thought that this would push air through my 3' air stone but same as the el cheapo K Mart one it doesnt - air comes out of the same places even and yes its a new air stone. BUT it is very quiet which is why I replaced the K Mart one - it went crazy noisy.”