(10/19/2011) - I bought the BB5k pump to replace a pair of PSK2500 pumps on my older [black accents]Octopus Xtreme 250 protein skimmer. The PSK2500 pumps are famous for having start up issues, and mine were no different. I did need an adapter kit made by CoralVue, [and not advertised for sale here at Premium, but available if ordering over the phone like I did]. Be advised CoralVue,[Maker of Octopus Skimmers] has updated the Octopus Xtreme skimmer. The new one is the Octopus XS 250 skimmer and has red accents, a longer cone neck, and is powered by PSK1000 pumps, [which do NOT have the start up issues of the 2500's]. This is important to note because there are two adapter kits, one for the PSK2500's, and one for the PSK1000's. The PSK2500's require the smaller adapter kit. This adapter kit will allow you to exchange 2 pumps for a single BB5k pump. I was able to use a 1.25 inch male pipe threaded plug to block the [now] unused side. The BB5k pump is more powerful, pulls more air, is quieter, and has no start up issues at all. Basically, I just upgraded my skimmer from a Octopus Xtreme 250 to a Super Reef Octopus 5000 Internal. Money well spent in my opinion.