Getting started
Start an aquarium that stays healthy
A buying and setup sequence that prevents the most common new-tank mistakes.
Begin with the fish you can actually house
Write down the adult size, water temperature, social needs, diet and lifespan of every species you want. A small fish at a shop may become a large adult; a schooling fish needs companions of its own kind; and a cold-water fish may not suit a heated tropical community. Choose a tank for the adult animals, then check that the stand can support the filled aquarium. Water weighs roughly a kilogram per litre before glass, substrate and equipment are added.
Use this setup order
- Put the tank on a level, stable stand away from direct sun and electrical hazards.
- Add rinsed substrate and secure any rocks or wood. Install an appropriately sized filter; add a heater only for species that need one.
- Fill with conditioned tap water. Run the equipment and check that temperature and flow remain stable.
- Build the biological filter before adding fish. Introduce an ammonia source and test regularly; the aim is a system that processes ammonia and nitrite to undetectable levels rather than merely clear-looking water.
- Introduce a small first group, then test and add livestock gradually.
Do not replace all filter media during routine cleaning. Beneficial microorganisms live on surfaces, especially in the filter. Rinse reusable media in removed tank water when flow slows, and replace only the parts that truly need replacing. Change a portion of the water regularly with conditioned, temperature-matched water. Keep a written log of test results, feeding and maintenance: it makes a developing problem much easier to spot.
How to choose a local fish shop
Bring your tank size, temperature, water-test results and current stock list. Ask the seller for the scientific name, adult size, origin, feeding routine and whether a fish has been eating. Look across several tanks: active fish with normal breathing, clean water and helpful staff are better signs than a low price. If the shop cannot tell you whether the fish will fit your setup, go home and research first. For “near me” searches, compare local maps and aquarium-club recommendations; no single national chain can substitute for seeing the actual animals.
Source and further reading
Aquarium Co-Op: nitrogen cycle
Check the scientific name and local laws for any species you plan to buy, keep, catch or release. Care needs vary by species and circumstances.