I am tinkering with the Forum's system scaling tool (developed by Dr Lennard and reworked for this site together with Sylvia) and started wondering about the depth for media beds used as mineralization sites. As the tool states, people typically use 300 mm (around 12 inch) beds, but that these can be deeper. The issue with depth is anoxia risk, but if you flood-and drain, how big is that risk in a deeper bed? If you convert the scaling tools' output for mineralization bed minimum requirements to a media volume, you will see that using 40 or 45 mm deep beds are far less restrictive in terms of ystem footprint. I would like to know if people using these deep media beds have any comments on anoxia risk.
With our standard fish food now being 41% protein, it will require me re-thinking the depth of media beds to avoid having a huge expanse of it for a family-sized system.