Reduce feeding for a few days to allow algal populations and alkalinity time to stabilize. Heavy rains can also cause alkalinity to decline. As feeding rates and pond temperatures increase, TAN and nitrite-nitrogen levels will increase. However, ponds which are highly enriched from years of accelerated production may have nutrient levels outside, usually above, these ranges. At this point, changes in nutrient concentration indicate changes in algal or bacterial populations if weather conditions are stable.
Algae use ammonia readily when sunlight is available.
If feed rates are constant, an increase in TAN concentration usually means that algal populations are declining. We are continuing efforts to find other accurate estimators for these parameters that are more suited to commercial growers. The catfish ponds used in this research had common levees, common water source, identical stocking and feeding rates. However, some ponds reacted differently to environmental and management stimuli. Important decisions, based on analyses from your ponds, may occur at DO or TAN concentrations other than those we found.