Choose your fish from one single category to ensure they will all get along well in the tank.
Cycling involves the growth of healthy micro-organisms within the tank, which will break down waste and help keep the water safe for fish. This takes a little time, and most experts recommend letting the tank run for at least a week before adding fish.
In case you’ve never heard the expression before, “cycling a tank” means to take the steps necessary to bring the water conditions up to where they are healthy for the fish. This is something that should be done before you ever add fish to your tank. In other words: You should not purchase your fish tank and your fish on the same day!
Etching a fish tank: 2 1/2-gallon fish tank
A Fish Tank with Goldfish in it.
I would encourage all fish keepers to gain an understanding of the nitrogen cycle as this will help you understand exactly what is going on inside your tank and how you can deal with water quality problems should they arise.The simple answer is yes, an aquarium must be cycled properly before you can safely add your fish. It doesn't matter whether the tank is 15 gallons or 500 gallons, it's still got to be cycled. If you were to simply fill your tank with water and then add all your fish at once then there would be such a massive buildup of ammonia, the chances are your fish would be dead within a few days.Traditionally, there are two ways to cycle a fish tank. Both methods will involve introducing ammonia into the tank which will be the food the bacteria need to survive. The most common method of cycling an aquarium is to use small community fish that produce the ammonia themselves. A kinder, more acceptable way to cycle a fish tank is to use a method called the "fishless" cycle. This also involves adding ammonia to the aquarium, but as a name suggests you do not use live fish. In this article, we are going to use fish as it's probably easier for a beginner to undertake, and we wouldn't be happy with youngsters handling pure ammonia as it can be dangerous. If you would prefer not to use live fish then read this article on how to carry out a fishless cycle.We would recommend that you use small community fish like the Barb. The Tiger and Cherry Barb are absolutely ideal as they are quite a hardy species of freshwater fish and unlike some more sensitive species, won't turn belly up as soon as they are exposed to ammonia. If you are cycling a very small tank less than 20 gallons then you are probably better off using much smaller fish like guppies or neon tetra. Your fish store should be able to give you advice based on what fish they sell.It's important not to add too many fish as this will create a large ammonia spike very quickly which will probably just kill the fish within a few days. For a 55 gallon tank, 10 barbs would be appropriate. For a 75 gallon tank, you could go up to 15, for 100 gallons plus, you're looking around 20 upwards.It's become quite popular to kick start the cycling process by seeding your new aquarium with biological media that already contains live nitrifying bacteria.The simple answer is yes, an aquarium must be cycled properly before you can safely add your fish. It doesn't matter whether the tank is 15 gallons or 500 gallons, it's still got to be cycled. If you were to simply fill your tank with water and then add all your fish at once then there would be such a massive buildup of ammonia, the chances are your fish would be dead within a few days.