What are the main differences between fresh water aquarium and salt water aquarium?

Answer 1

Salt water aquariums require much brighter lighting and more water movement then regular aquariums. They also require many more gallons/fish. Worms and other small life-forms play an important part of maintaining a healthy saltwater tank and it often takes at least two years for a tank to become properly mature and for corals to start thriving.
A

Answer 2

Salt water aquariums require a lot more maintenance for balances of the amount of salt and the PH balances in the water. Also from my experience salt water fish seem to be a lot more delicate. But the bright side is that the hard work pays off. The fish you can have in a salt water aquarium are a lot brighter and are more appealing to look at.

Answer 3

There are a lot more water parameters to keep in check with a Marine system, but also the disease control is a bit more of a challenge. For example - Marine Ich is a lot worse than Freshwater Ich (and believe it or not - the 2 are not the same or even closely related).

http://www.reef-aquarium.net/resources/disease/ich.html
http://reefkeeping.com/issues/2005-10/sp/index.php

Answer 4

the salt water is full of salt. thats for the fish who needs loads of salt. the other has not that much salt, and needs fresh water to survive. they need filters {freshwater}.

Answer 5

a freshwater is a lot easier to maintain and for people who have less patience. salt water is very difficult and can get very impatient to do.

Answer 6

The salinity of the water.

Answer 7

fresh water:

easy maintenance
plain fish
easy to clean
easy to add water

salt water:

tough maintenance
colorful fish
hard to keep clean
hard to keep well balanced

just depends on your patience level and time.