Marine vs Fresh Water Fishes

Setting up an aquarium is not too difficult ...

For fresh-water :

Preferably put in differents grades of sand and pebbles

Suitable fishes would be goldfishes or guppies (can be commonly found in drains).

For salt-water :

Preferably put in differents grades of sand and pebbles

Suitable fishes would be the butterfly (a slim elegant fish but need optimal care).

Air pumps & good water filtration systems, using carbon, are essential for the well-being of the fishes. Other items include hygrometers, test kits for CO2, etc, marine plants.