The tank that looks effortless on Instagram usually got that way because someone did the boring steps first. This guide walks the lowering pH guide from empty glass to stable, livable water without the usual week-two crash.
What you need
- A 20-gallon tank and a stand rated for the weight (~80 kg when full).
- Filter rated for at least 80 L/h.
- Heater (if tropical): 167 W.
- Substrate: 5 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 in a planted tank — for 39 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 39% water change weekly, using our introducing new fish safely guide 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.
Shrimp-friendly tweaks
For shrimp, soften the flow, add moss and leaf litter, and keep nitrates low. A 20-gallon planted tank with stable parameters lets shrimp moult and breed without the stress fish would add.
