It may seem like a fresh, new, sparkling clean, unused tank would be the ideal habitat for fish, but novice aquarium owners often kill fish by adding them to a tank before it is ready. Without the appropriate chemistry, the tank lacks suitable bacteria to filter toxins and waste out of the water, a condition called new take syndrome, but it is easy to take steps to prepare a tank to become a healthy, suitable home for different types of fish.

1. Do Your Research
   Keeping fish is more than just dunking them into a bowl of water and hoping for the best. Before getting started with an aquarium, learn about the specific needs of different fish as well as basic aquarium maintenance so you are ready to provide a healthy habitat for fish to enjoy.
   
   
2. Buy the Right Equipment
   Different fish need different water temperatures, tank sizes, and plants to feel at home in your aquarium. Choose the best quality supplies that fit your budget, and coordinate what you will enjoy with what fish need the most.
   
   
3. Assemble the Tank Properly
   Carefully assemble the tank, washing all parts – including gravel, plants, and accessories – in distilled water during assembly to remove any contaminants that could upset the tank's balance. Ensure all parts are working properly, and make adjustments to location, heat, or other conditions as necessary.
   
   
4. Cycle the Aquarium
   Before adding fish, it is essential to allow the tank to cycle with plants for several days or weeks so it can achieve a healthy biological and chemical balance with a fully functioning natural filter. Hardy fish may be able to be introduced to the tank earlier, but watch fish carefully for any signs of stress.
   
   
5. Add Fish Slowly
   Once your tank is ready for residents, add fish only 1-2 at a time so the tank can adjust to its new occupants and the filter is not overwhelmed. Rearranging plants and changing water can help fish adjust to their new home by helping them acclimate more quickly and removing any territorial boundaries that already resident fish may have established.

In time, your new aquarium can become a healthy, thriving marine ecosystem, if you've taken the proper steps to introduce fish in a controlled and compatible way.