Most people that want to keep fish as a hobby usually choose fresh water fish instead of Salt water fish because they are easier to maintain. But after gaining more experience with fish, they start considering the switch to Salt water fish. There are a much larger variety of oceanic aquatic creatures than fresh water could ever offer; Salt water fish fascinating and much better looking fish.
The more endurance of fresh water fish to the water and temperature conditions and commonly make them a good choice for beginners. Their adaptability is due to constantly changing condition of the fresh water; that makes them more resistant than Salt water fish that usually live in environment that provide a constant quality of the water. Considering that the ocean has such a volume of water that any chemicals disturbances are diluted instantly, Salt water fish have no need to adapt.
The obvious difference between the environment of fresh water fish and Salt water fish is the level of salt in the water. Fresh water fish have a greater amount of salt in the body then there is in the water so water is constantly transferred in and out of the fish's cells by osmosis. Salt water fish are the exact opposite: their environment contains more salt than their body, so in order to remain healthy they have to drink and eliminate water constantly.
The most important aspect of maintaining Salt water fish is matching the gravity of your aquarium to the specific gravity that your specie of Salt water fish is used to. Gravity for Salt water fish is related to the level of salt in the water, so once you find our what your Salt water fish is comfortable with, keep it at a constant.
