What You Need Before You Buy the Fish
The most important rule in fishkeeping: set up the tank before you buy the fish. This means completing the nitrogen cycle, stabilizing the temperature, and establishing plant growth before a betta enters the water. Most betta deaths in the first week of ownership are caused by adding the fish to an uncycled, unstable tank.
Shopping list for a 10-gallon betta setup in Cambodia: 10-gallon rectangle glass tank with lid, 50W adjustable heater, sponge filter with air pump, substrate (black sand or natural gravel), 3-5 live plants (java fern, anubias, or water sprite), driftwood or smooth cave décor, liquid dechlorinator (Seachem Prime), API liquid test kit, digital thermometer, timer for lights.
Total cost in Cambodia: approximately 80,000-150,000 KHR ($20-40 USD) for basic setups to 500,000 KHR ($120 USD) for a high-quality planted display. Equipment lasts for years — the per-year cost is very low.
Substrate and Hardscape First
Rinse your substrate under running water in a bucket until the water runs completely clear. For black sand, this takes 5-7 rinses. For gravel, 3-4. Never skip this step — dust in substrate clouds water for days and irritates gills.
Add 3-5 cm of substrate to the tank. Place your heavier hardscape items (driftwood, rocks, caves) before adding water — repositioning heavy items in a full tank is difficult and often cracks glass from sudden pressure changes.
Tip for Cambodia: driftwood and rocks collected from rivers outside the city should be boiled or bleach-treated and fully rinsed before aquarium use. Untreated wild-collected materials introduce bacteria, parasites, and chemicals.
Equipment Placement
Heater: place it diagonally near the filter output so heated water circulates throughout the tank. Submersible heaters should be fully underwater — only the adjustment dial should be above water. In a 10-gallon tank, place the heater on one of the back corners pointing across the tank.
Sponge filter: place it in one of the back corners. The rising bubbles create a gentle circulation that keeps water oxygenated without strong current. Connect air tubing to an air pump rated for your tank size, placed above the waterline or with a check valve to prevent backflow if the power goes out.
Thermometer: position it on the opposite end of the tank from the heater to measure the actual temperature throughout the tank, not just near the heat source.
- ✦Run all equipment before adding fish — verify heater holds target temperature for 24 hours
- ✦Hide equipment behind plants and décor for a cleaner look
- ✦Heater should never touch substrate — keep it elevated
Adding Water and Cycling
Fill the tank slowly using a plate or plastic bag on the substrate to prevent disturbing the layout. Add liquid dechlorinator to the tap water before or immediately after adding to the tank. Use Seachem Prime at the standard dose — it removes chlorine, chloramine, and temporarily detoxifies ammonia and nitrite for 24-48 hours.
Cycling the tank before adding the betta takes 4-6 weeks but protects the fish completely. To cycle: add pure ammonia to 2 ppm (or add a small pinch of fish food to decompose), run the filter, test ammonia and nitrite every 2-3 days. When both read zero within 24 hours of ammonia dosing, the cycle is complete.
To speed up cycling in Cambodia: add a handful of established filter media or gravel from a friend's healthy tank. This seeds your filter with the bacteria you need and can reduce cycling time to 1-2 weeks. Bottled bacteria products (Seachem Stability) also help and are available in Phnom Penh aquarium shops.
Adding Plants
Live plants can go in during cycling — they benefit from the ammonia spike as a nutrient source. Attach java fern and anubias to driftwood with thread or aquarium-safe superglue. Do not bury their rhizomes (the horizontal root stem) — bury only the roots. Buried rhizomes rot and kill the plant.
For Cambodia's typical low-light apartment conditions, choose plants that need minimal light: java fern, anubias varieties, water sprite, and hornwort grow well under a single basic LED. If you want carpet plants or red plants, you will need a stronger light (Fluval Plant 3.0 or similar) and CO2.
Plants in a betta tank serve multiple functions: they consume ammonia and nitrate to keep water clean, provide shade and hiding spots that reduce betta stress, and produce oxygen during daylight hours that benefits the fish.
Introducing Your Betta Safely
After cycle completion, do a 30% water change to bring nitrate below 20 ppm. Then float the bag or cup the betta came in on the surface for 15-20 minutes to equalize temperature. Over the next 30-45 minutes, add small amounts of tank water to the bag every 10 minutes to acclimate the fish to your water chemistry. Net the fish out and release it — do not pour transport water into the tank.
Do not feed the betta on day one. The stress of transport suppresses appetite and digestion. Offer one or two pellets on day two. If the fish does not eat, wait another day — this is normal adjustment behavior.
First two weeks: watch closely for signs of stress (clamped fins, hiding constantly, pale color, heavy breathing). If water quality is good and temperature is stable, the betta should begin exploring and displaying normal behavior within 3-5 days.
- ✦Turn off aquarium lights during the first 24 hours to reduce stress
- ✦Do not tap the glass or startle the betta for the first week
- ✦Offer a mirror for 1 minute on day 3 — a healthy betta will flare confidently
Weekly Maintenance Routine
A sustainable weekly routine keeps betta tanks healthy with minimal effort: every week, remove 25% of tank water with a gravel vacuum (siphon waste from the substrate), replace with fresh dechlorinated water at the same temperature, wipe algae from glass with a clean magnet scraper, check heater temperature, and observe the betta's behavior and fin condition.
Every month: test water parameters with the API kit (ammonia, nitrite, nitrate, pH), rinse sponge filter media in old tank water (never tap water — chlorine kills the beneficial bacteria), and trim any overgrown plants.
In Cambodia's climate, weekly water changes are especially important during the hot dry season (March-May) when evaporation concentrates waste faster, and during the rainy season when ambient temperature fluctuations can stress fish.