Which pump have gone bad on the RO Dc or AC?I have both. I have had two Reef octopus skimmers going for 8+ years. Been happy with them but feel like I have to replace the pumps more often than I should (on 3rd of 4th pump on my largest one). I have a Nyos 120 on my Red Sea 170 and have liked it (6 months into it). It is very quiet (but also a lot smaller than my Reef Octos). The build quality on the Nyos is a bit higher but have not seen it perform better than the Reef Octopus. On the Reef Octopus skimmers I run Avast Marine swabbies and external skimmate storage so I don't touch them but every few months.