I would idealy go from 1 foot to 5 foot + and make the sides sloped so its hard for a herring to land. With it being a sloped bottom the fish can get into the deeper water in winter and move into the shallower warmer water in summer

To keep you water clear i would use a UV light tube and an eco filter it will filter the water nicely.


I would also have a couple of golden orf in the pond as they are very suseptible to disease so if there is a problem in the water they will die first it will give you enough time to test and treat the water.


If you want anymore info just PM me mate