The 2nd-stage bacteria (Nitrobacter winogradskyi) reproduce slower than the 1st-stage (Nitrosomonas). Stalls of 2-4 weeks are normal.
Nitrobacter prefer 78-82°F. Below 72°F they nearly stop reproducing. Raise heat to accelerate.
Bacteria need pH 7.4+. If pH dropped below 6.8 from acidic water, nitrification slows. Test pH; raise with crushed coral or Seachem Reef Buffer if needed.
High salt levels (above brackish) inhibit Nitrobacter. Avoid medicating during cycling.
Dose Seachem Stability or Bio-Spira at recommended dose. Pre-cultured Nitrobacter speeds the second stage.
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