I have set up tanks that crashed in week two and tanks that are still stable years later. The difference is almost never luck. This guide walks the high-tech CO2 tank from empty glass to stable, livable water without the usual week-two crash.
What you need
- A 30-gallon tank and a stand rated for the weight (~120 kg when full).
- Filter rated for at least 120 L/h.
- Heater (if tropical): 86 W.
- Substrate: 4 cm deep.
- Live plants and a light on a 7-hour timer.
Step by step
- Rinse substrate, add it, and hardscape before filling.
- Fill slowly to avoid clouding; start the filter and heater.
- Cycle the tank — see a solid lymphocystis: the 'cauliflower' wart virus in fish — for 20 days until ammonia and nitrite read 0 ppm.
- Test water, then add a small group of hardy fish; build up slowly.
Common mistakes
Adding fish during the first week, skipping the cycle, and skipping water tests are the big three. A 27% water change weekly, using our cherry shrimp care: a colourful, low-tech cleanup crew guide, prevents most problems before they start.
Next steps
Once stable, layer in more plants and a few peaceful tank mates. Keep a log of parameters; a tank you measure is a tank you can trust.
