A week into our Walstad journey, and the tank is settling into a rhythm. Water is crystal clear, plants are adapting, and the nitrogen cycle is progressing exactly as we hoped.
Test Results (Days 7-10)
| Parameter | Day 7 | Day 10 | Trend |
|---|---|---|---|
| Ammonia | 0.5 ppm | 0.5 ppm | Stable |
| Nitrite | 0.25 ppm | 0.25 ppm | Stable |
| Nitrate | 0 ppm | 0 ppm | Same |
| pH | 7.6 | 7.6 | Stable |
Reading Between the Numbers
At first glance, stable readings might seem boring. But this stability is actually significant—the ammonia hasn’t spiked despite the organic soil continuously releasing nitrogen compounds.
What’s happening: Our plants are absorbing ammonia faster than the soil releases it. This is the “silent cycle” in action.
The zero nitrate reading is interesting too. In a traditional cycle, you’d see nitrates building up. Our plants are apparently consuming nitrates as fast as they’re produced. Classic Walstad behavior.
The pH rose slightly to 7.6, which is within normal range. Our coral hardscape might be contributing a small amount of buffering.
Plant Adaptation
Two weeks in, and we’re seeing the first real signs of adaptation:
Winners:
- Water Wisteria: Growing visibly! Several stems have grown 2-3 inches. The feathery leaves are multiplying, creating that lush jungle look we wanted.
- Dwarf Sagittaria: Starting to send out runners! We spotted new baby plants emerging from the substrate, connected to mother plants by thin runners. The carpet is beginning.
- Red Root Floaters: Multiplying already. Coverage has increased from 30% to maybe 40% of the surface.
Adjusting:
- Amazon Swords: A few older leaves yellowing (normal transition), but holding steady overall.
- Cryptocoryne: The infamous “crypt melt” has begun—some leaves dissolving. But we can see tiny new leaves beginning to emerge from the crowns. Hopefully the worst is behind us.
- Java Fern: Unchanged. This plant operates on geological time scales.
About Crypt Melt
The Cryptocoryne melt is completely expected and actually a sign they’re alive. Here’s what happens:
- Crypts are grown in nurseries under specific conditions
- When moved to your tank, conditions change dramatically
- The plant abandons its existing leaves (which aren’t suited to new conditions)
- New leaves grow adapted to your specific water
It looks alarming—leaves literally dissolving—but the crown and roots are fine. In 2-3 weeks, we should see healthy new growth.
The Biofilm Grows
The thin glass film we noticed on Day 3 has thickened. There’s also a layer forming on the sand surface and decorations. This “gross” stuff is actually a sign of a healthy, maturing ecosystem.
Once we add our Nerite snails, they’ll feast on this biofilm. But for now, we’re letting it develop.
Looking Ahead
Based on our research, we should expect:
- Days 12-14: Ammonia should start dropping more noticeably
- Days 14-16: Nitrite might spike as the second phase bacteria lag behind
- Days 21-28: Both should reach zero if all goes well
We’re on track. The silent cycle hypothesis is looking more likely with each test.
Still No Action Needed
With parameters in safe ranges, we’re staying hands-off. The temptation to “help” is strong, but intervention at this stage usually does more harm than good.
Our only tasks:
- Monitor temperature (holding steady at 75°F)
- Test every 3-4 days
- Remove any completely dead plant leaves
- Wait
The cycle continues.
Status: Silent cycle progressing - plants absorbing ammonia and nitrate