Throughout the cycle farmers either regularly managed water or
used treatment only at times of poor water quality. Aeration with
paddle wheels was common (78%) and one farmer used an air jet.
Water was exchanged every 12 days on average to maintain water
quality or was topped up to compensate for losses due to evaporation
and seepage. Generators fueled by diesel were the most common
source of energy to power electrical aerators and pumps (97%).
Fertilization was not common, only occurring on 6% of farms. Many
farmers believed it was unnecessary and would cause plankton
blooms. Water quality in ponds was measured by 43% of respondents;
all of them measured pH on a weekly to monthly basis. A few farmers
measured alkalinity, dissolved oxygen, ammonia, nitrite, and nitrate.
Periods of poor water quality were experienced by 41%; most common
treatments included lime, dolomite, zeolite, or water exchange to
control pH. Farmers who did not measure water quality reasoned that
they lacked equipment or did not know how, and one said it was
useless. Those who did not monitor water quality relied on visual
inspection to assess pond health.