The Free On-line Aquaculture Dictionary

Nitrification activity in relation to temperature (in a well designed filter)

Temperature oC g m2 day-1 ammonia converted to nitrate by bacteria in filter
5 0.3
10 0.5
15 0.7
20 0.9
25 1.0
Note that the above figures are a guideline only. Conversion rate may differ due to water quality (including oxygen levels, pH and organic loadings) and filter design (especially water distribution patterns).