This was an idea Praew and I came up with. We will be experimenting with slow sand filters to treat the grey water sewage before using it for watering plants and realized we should filter for any loose hair or whatever that gets down the drain so it doesn’t clog the pump. Therefore, before the main grey water storage cistern, we added a small chamber in which we can install a pre filter. The grey water comes in from the right side, gets filtered in the small chamber before being dropped into the larger chamber to the left: