Thanks for the info.
This was for a friend. She wanted the setup like the PF40-UV, but needed it for a 55g tank. That's why I started looking into the PSE1. She has a canister already setup (fluval) and wanted to use the hob as a mechanical filter and also wanted UV to attack any bad bacteria.
Do you make a UV hob filter big enough for a 55g? Or would the PSE1 be it?