We recently had a koi pond installed by a company using Aquascape products
(biofilter, skimmer, pond liner covered with gravel). We live in the South
Bay area of Los Angeles. We just had a new koi get sick and I did a little
sleuthing on the net and it seems that the gravel of the bottom of the pond
collects debris where bacteria and other organisms can breed. Has anyone
had success with koi in a gravel bottom pond? Thanks.