To make a saltwater it takes more than just water and some salt it takes effort, equipment, research and knowledge. A saltwater aquarium can be very relaxing if done right. There can be more than one part to this hobbie that can puzzle you so that's where the research and knowledge comes in. To keep the saltwater aquarium running you need equipment, and to keep it going on for years to come you need determination and effort. A saltwater aquarium is much like a puzzle, if you don't have all the peices you can make the puzzle, at least not right. On this page I will explain a few points of making a saltwater aquarium.
Equipment is necessary, you need it to keep the aquarium in good condition and to keep it running. If you don't have the right equipment you could have a major problem and cause your aquarium to "crash". I will explain the necessities for equipment.
A sump is an extra aquarium below your main tank that holds extra equipment and does some natural filtering. There can be 4 different parts to it. The first compartment is where the water is coming in from you tank by some piping, it usually holds your skimmer. Then you have 3 baffles (a divider), each an inch apart. The first one and third one are both lower than the middle baffle. This makes a bubble trap, taking out all the nuisance micro bubbles. The water will flow through the bubble trap into a refugium, which is a compartment that can hold some live rock, live sand, cheato and your heater. You can put some of your frags (fragements of corals) into it, so that they can aclimate in there before you put them in the main tank. After the water goes through the refugium it goes over a last baffle into a compartment holding your return pump which pumps the water from your sump back into the main tank. If you have a nano, you most likely won't need a sump.
A RO/DI filter is basically a filter that you hook up to the faucet, it will take out all the harmful chemicals in the water like chlorine, chlorimine and other chemicals. It will make the tank less prone to get nuisance algae and keeps it cleaner for the fish. The water from a RO/DI filter is better than tap water with a chemical additives because it is supposedly better for the corals and fish.
You have a heater to keep your temperature between 78-82 Fahrenheit or 25-27 Celsius. It is better to have 2 heaters in a bigger aquarium because if one dies it won't make the temperature drop. Or gp sky high, killing your fish by boiling them.
Saltwater aquariums can have a different lighting than others. If you want to get suitable lights for your aquarium you have to see what you corals need. If you don't have any corals and it is a FOWLR or fish only aquarium you can use a light that is put on a freshwater aquarium. Once you find out what kind of lighting you need you should consider how you want your corals to react. If you have a lower k lighting it will make your corals more of a bleachy colour because the light put out will be more white, but if you use around 13-15k lighting you will have a more vibrant reef because the light put out will be more of a blueish colour. You can also change the colour of the corals by using actinic bulbs which are around 20k, they are kinda mimicking the moon, they are really blue. There are different types of bulbs you can buy, there are VHO (very high output), PC (power compact), MH (metal halide) or T5 (flourescent like) bulbs. What kind of bulb you buy you buy can change the corals colour and the money in your pocket because the bulbs that you want to buy can cost more than others.
Are a easy way of keeping your water clean and pure. They are very many varieties of skimmers you can buy right now. The skimmers take all the harmful waste out of your water and putting it in a cup at the top of the skimmer. What the skimmer does is put air into a column of water into a chamber of the skimmer, the bubbles created will grab on to the waste and put it into the cup. About every week or so you take out the cup and wash it. A good skimmer can cost around 150$-9999999999999$. It depends how many gallons of water you have in you main tank and sump.
Power Heads are like little fans in your aquarium that circulate the water. If you put effort into making sure the water circulates so that there are no "dead" zones it will reduce the amount of nuisance algae in you tank. Different wastes and toxins can grow in a tank with water that has gone stagnate. If you point the power head towards the surface it will make a nice rippling effect but that ripple will help create good gas exchange and will help avoid stagnate water and oil like junk on the surface of the water.