I'm pretty sure a Tang is a salt water fish but if you have a fresh water (regular) fishtank, I'm not sure just adding salt will do it. I believe you have to have a salt water setup... check with a pet store that sells Tangs in your area.
one time a month
No just fresh water and a loving home! :)
Saltwater fish require salt water, and fresh water fish need fresh water, you can't mix them, or the fish will die. You need to look at each individual fishes needs as to what temp they need their water to be. There are some saltwater fish that can survive in fresh water, but it is not healthy for them.
water an air pump small with hose to oxinate the water so they can breath filter and water pump
That depends on how big the tank is. Small tanks that are easy to carry can have most of the water removed and then be picked up and relocated. Larger tanks will need to have the fish, water, plants, rocks etc removed and then be re landscaped after it has been relocated.
purple TANG
Because fish have gills and can breathe under water and humans do not
Fish tanks are often used to make terrariums, but to support aquatic life (fish) one needs to use the tank as an aquarium. For supporting land-living life (terrestrial life) one needs to user the tank as a terrarium. Aquariums need to be water tight, while terrariums may or may not need to be.
Check with the people who sold you the tank and or fish; they may have some ideas. You can't put fish right into water from the tap; if you did that it probably accounts for their discomfort. You need to condition the water to remove the chlorine. Tanks also need to be at the right temperature, and adding fish to tanks that are are a different temperature from their travel bags is really a shock to them. There are various conditioners you can get. There is also a special salt (yes, salt) that you can put into fresh water tanks; the salt is calming to the fish. Naturally, you put in only the amount given in the instructions. The people at the store may recommend some medications to add if there are symptoms that you can describe to them. Don't be discouraged; new tanks need to be conditioned over time, and they need to contain some healthy bacteria that will develop over time as well.
It sounds like your fish has fungus over its eyes and skin. That indicates terrible water conditions. All fish need to have clean water. Change the water! Successfull fish keepers change at least a part of a tanks water weekly.
Filters keep the water clean for the fish, kind of like we need clean air to breath properly. Also, filters keep the tank clean by (yep you guessed it) filtering the water. I hope this helped^^
Tang are a marine species but they still need the same kind of feeding programme that most other fish need. That is at least 2 feeds daily (morning and evening) and only as much as it can eat in 15 minutes.