1. Choose the right aquarium
Base volume on adult size, swimming behavior, social needs and filtration capacity.
2. Cycle the system
A mature biological filter supports nitrifying microbes that process ammonia and nitrite.
3. Match water chemistry
Research species-specific temperature, pH, hardness and salinity requirements.
4. Provide oxygen
Surface agitation, filtration and appropriate stocking help maintain dissolved oxygen.
5. Feed appropriately
Match diet to natural feeding ecology and life stage.
6. Reduce stress
Use compatible tank mates, hiding places and suitable lighting.
Water parameters
What to monitor
There is no universal aquarium target for every fish.
| Parameter | Why it matters | Note |
|---|---|---|
| Temperature | Metabolism, immunity and development | Match species range; avoid abrupt swings. |
| pH | Physiology and chemical availability | Species and source-water dependent. |
| Ammonia | Toxic nitrogen compound | Should be controlled through cycling and husbandry. |
| Nitrite | Can disrupt oxygen transport | Should not accumulate in a mature system. |
| Nitrate | End product of nitrification | Manage through maintenance and stocking. |
| Dissolved oxygen | Essential for respiration | Warm water holds less oxygen than cool water. |
| Hardness | Mineral balance | Important for osmoregulation in some species. |
| Salinity | Critical in marine/brackish systems | Measure accurately and keep stable. |
Beginner checklist
Before adding fish
□ Research adult size
Do not plan a tank around juvenile size.
□ Test the water
Know the baseline before stocking.
□ Confirm compatibility
Check chemistry, temperament and predation risk.
□ Plan maintenance
Observation and water-quality checks are essential.
FAQ
Beginner questions
No. Temperature, pH, hardness and salinity requirements differ between species. Research the exact fish before setting targets.
There is no single universal schedule. Test water quality, consider stocking and filtration, and follow species-appropriate husbandry guidance.
No. Marine and freshwater fish have very different osmotic requirements. Brackish-tolerant species are a separate case and still require species-specific conditions.
Larger volume can improve stability, but shape, swimming space, filtration, social needs and species behavior also matter.