Flavobacterium spp. infections (columnaris, bacterial coldwater disease, bacterial gill disease) can be devastating for aquaculture businesses. F. columnaris alone caused $40-50 million in losses to aquaculture operations in 2015. The typical treatment methods include antibiotic feeds for internal infections and applications of potassium permanganate, hydrogen peroxide or chloramine-T to combat infections on the outside of the fish.
Past research has indicated that bacteria can bind to inert particulates. In 1915 kaolin clay was tested as a treatment for removing bacterial from the throat and nose. More recently kaolin clay has been researched for removing flavobacterium from fish culture tanks, with promising results.
Starting in June of 2024, weekly kaolin clay treatments of 1 g/l for one hour were added to trout fry tanks in a hatchery to gauge; 1) the physical tolerance of small trout (three-week old, 1500/lb) to kaolin clay, 2) if there is a hindrance to growth, and 3) anecdotally evaluate if there is a reduction in fry mortality while fish are in the hatchery.