viper/Alan,I have build 1 but I went to big, I think. 15cm * 15cm * 50cm * 2 with a 2400LPH pump. The reactor is used for a 700L setup with 20% softies, 40% LPS and 40% SPS.It does work but it’s not fluidized another problem I want to build 1 for a 2000 – 3000L setup.I need to change the pump size or build a small unit but to do that I need to understand what is the size reactors used by others with the pump size, etc.