Three days since our first water change, and we’re not out of the woods yet. The nitrite plateau continues, testing both our patience and our snails’ resilience.
Test Results
| Parameter | Day 18 | Day 19 | Notes |
|---|---|---|---|
| Ammonia | 0.25 ppm | 0.25 ppm | Stable |
| Nitrite | 2.0-5.0 ppm | 5.0 ppm | PLATEAU |
| Nitrate | 0-5 ppm | 5 ppm | Present |
The Nitrite Plateau Is Real
We hoped to see nitrite dropping significantly after the Day 16 water change. Instead, it climbed right back to 5.0 ppm. The NOB bacteria are working—we know because nitrate is present—but they can’t keep up with nitrite production yet.
This is apparently common. Some tanks stay elevated for days or even weeks while bacterial populations adjust. We’re now four days into sustained high nitrite levels.
It’s frustrating, but there’s no shortcut. The bacteria reproduce at their own pace.
Days 18-19 - The nitrite plateau continues
Snail Stress and Our Second Water Change
By Day 19, our snails were showing stress again—two at the rim, reduced activity. Time for another intervention.
We did another 25% water change:
- Removed 5 gallons
- Replaced with dechlorinated, temperature-matched water
- Skimmed surface biofilm again
After the change, all three snails descended from the rim and resumed grazing within an hour. Immediate improvement.
The Math of Water Changes
At 5.0 ppm nitrite, a 25% water change theoretically reduces it to about 3.75 ppm. Not dramatic, but enough to give the snails relief. We can’t do massive water changes (50%+) because that would shock the developing bacterial colonies.
It’s a balancing act: keep snails alive while letting bacteria establish.
Plant Observations
Despite the nitrite stress, the plants continue growing:
Water Wisteria: Now noticeably taller than at setup. The jungle effect is becoming real.
Dwarf Sagittaria: Runners spreading! We count at least 5 new baby plants emerging from the substrate.
Crypts: Recovery mode. New leaves growing from most crowns. The melt is ending.
Red Root Floaters: Covering about 50% of the surface now. Need to thin them soon.
The plants give us hope. A thriving plant mass means the ecosystem fundamentals are sound, even if the bacteria haven’t fully caught up.
Silver Linings
Despite the frustrating plateau, there are positive signs:
- Ammonia stays low - AOB bacteria are solidly established
- Nitrate is present - NOB bacteria ARE working, just slowly
- Plants keep growing - The ecosystem foundation is healthy
- Snails survive - They recover after water changes
The cycle IS progressing. Just slower than we’d like.
Status: Nitrite plateau - Day 4. Snails stressed but recovering after water changes.