Nitrite is crashing—in the best possible way. We’re days away from a fully cycled tank.

Test Results

Parameter Result Trend
Ammonia 0-0.25 ppm Stable
Nitrite 0.5-1.0 ppm DOWN from 2.0!
Temperature 75°F Stable

Nitrite Halved in Two Days

This is the breakthrough we’ve been waiting for. Nitrite dropped from 2.0 ppm to 0.5-1.0 ppm in just two days. The NOB bacteria colony has reached critical mass and is now processing nitrite efficiently.

At this rate, we could see zero nitrite within 3-5 days.

The Math

  • Day 16: 5.0 ppm (peak)
  • Day 23: 2.0 ppm
  • Day 29: 2.0 ppm
  • Day 31: 2.0 ppm
  • Day 33: 0.5-1.0 ppm

After nearly two weeks of plateau and slow decline, the crash is happening. Exponential bacterial growth in action.

Tank on Day 33

Day 33 - The final countdown to cycle completion

Bladder Snail Census

We did a count of our hitchhiker bladder snails: 24+ tiny babies now visible. That’s up from ~6 on Day 30.

Before panicking about population explosion, remember:

  • They’re all juveniles (rice-grain sized)
  • They won’t reach breeding maturity for another 6-8 weeks
  • They’re actively helping with our algae problem
  • We have a plan: cull any pea-sized adults after our January trip

For now, they’re free labor.

Pre-Trip Planning

We’re leaving for a two-week trip in late December. The timing is actually perfect:

  • Cycle should complete by Dec 19-21
  • Tank can self-maintain during our trip
  • Snails have plenty of algae and biofilm to eat
  • Plants are established and growing
  • Heater will maintain temperature

Before we leave, we’ll:

  1. Do one final water test (confirm cycle complete)
  2. Top off the water level
  3. Confirm the light timer is set correctly
  4. Trust the ecosystem

Cycle Completion Target

Expected completion: December 19-21, 2025

That’s 36-38 days since setup—right in line with typical Walstad cycling times. The extended nitrite plateau added about a week, but we’re finishing strong.

Status: NITRITE DROPPING FAST (2.0→0.5-1.0 ppm in 2 days!) - ~3-5 days to completion

Next test: Day 35-36 (Dec 18-19)