Buying new fish for your aquarium is exciting! Whether you're new to the hobby or a seasoned veteran looking for something new and interesting to add to your aquarium, going to the fish store is just plain fun. There are so many fish to choose from you might have trouble deciding what to buy, and you could find yourself wanting them all! But before making any livestock purchase, there are some important questions you should ask to make sure you're making the right decisions for yourself and the fish.
1. How big will the fish get? Many of the pet fish species you see in the store aren't fully grown. Some may only get a little bigger, while others may double, triple or more in size. Always make sure the fish you intend to buy will fit comfortably in your aquarium when they reach adult size.
2. What does the pet fish eat? While most tropical fish do just fine on a diet of flake, pellet or frozen foods, some species are specialized feeders that may require live food or customized feeding methods. Some pet fish may grow up to eat the rest of the fish in your tank, while others may be herbivores that will decimate a beautifully planted aquarium. Before purchasing any new aquarium fish, make sure you have the means and dedication to properly feed it and that it won't devour the rest of your aquarium's inhabitants or plants.
3. Is the fish species peaceful or aggressive? If you have peaceful fish, you don't want an aggressive fish that spends its day chasing everyone else around, stressing them. On the other hand, if you have rambunctious fish, you wouldn't want to add a shy fish that will be constantly harassed and running for its life. While some fish may not kill their tankmates outright, being chased, nipped and kept from feeding will eventually take its toll on the victim, resulting in increased susceptibility to disease or even death. Click here to learn more about fish personalities.
4. Is the fish territorial? There's a difference between being aggressive and being territorial, although some fish can be both. Territorial fish will often tolerate other tank inhabitants as long as they have enough space and structure to define their territorial boundaries. They may chase other fish away if they come too close, but they will otherwise leave them alone. Territorial fish often do not tolerate other members of their species, so it's best to just buy one.
5.Will it get along with my fish? Keep a list of the fish you have in your aquarium. If you've forgotten or aren't sure what kinds of fish you have, take pictures to show store staff so they can help you make the right choices. Learn more about fish compatibility in our helpful article Fish Compatibility: How to Build a Peaceful Community Fish Tank.
6. Does it need special water parameters or temperature? While most tropical fish sold today are raised in captivity and tolerate a certain range of water chemistry parameters, some are still collected in the wild and may need a specific pH, alkalinity or temperature to thrive. Always research the type of fish you intend to buy or ask if they need special conditions.
7. How many fish should I buy? Some fish are solitary and as adults they do not tolerate others of their own kind or closely related species: betta fish, certain gouramis, redtail and rainbow sharks, and some cichlids are good examples. Schooling fish (tetras, barbs, danios, rasboras), on the other hand, do best in groups of 6 or more and may hide or become stressed if kept individually or in smaller groups. Livebearing fish (guppies, mollies, platies and swordtails) do best in a ratio of two females to one male as the males tend to be relentless in their efforts to mate.
8. How long do pet fish live? Small fish like tetras, barbs and danios should live at least 5 years, if not longer, while medium sized fish such as angelfish and goldfish often live 10 to 15 years. Larger cichlids, clown loaches, and many plecostomus and catfish species can live 20 years or more, while koi are known to live even longer. Plan accordingly.
9. How long has the fish been in the store? Never buy a fish that has just arrived in the store. Shipping stress temporarily lowers a fish's resistance and increases its susceptibility to disease. Moving it again without giving it a few days to stabilize will only compound the problem. This is especially true of wild caught or delicate species.
10. What part of the aquarium will it occupy?Many fish spend their time at specific levels in the water column, and it's important both visually and in terms of compatibility to have equal proportions of surface, mid-water and bottom dwellers. Crowding fish in any layer may result in conflict and stress to some of them.
11. What type of habitat does it need? In nature, fish occupy specific habitats such as open water, plant beds, rock structure or fallen trees. Always research fish before you purchase them and make sure you have the proper habitat in your fish tank.
Asking key questions and making sure you have the right conditions for fish before purchasing them will ensure they live long and happy lives and result in many years of enjoyment with your aquarium
Enough talking about the challenges — what do you actually need to build a small and simple aquascape?
You will need the aquarium itself. Nano aquariums (around 30 liters and less) are getting quite popular because they don’t take up too much space and are easy to maintain. What you should be aware of is that the smaller the aquarium, the higher the risk that changes in the environment — like temperature and water quality — will take effect on your aquascape. Bigger aquariums are more stable because changes in the environment have a smaller effect. I have a 30x30x30cm cube and a 30x60x20cm tank. Both are running quite stable, but in the summer they need some good cooling with a small fan and I have to add some water daily to compensate the water evaporation. You should always put a soft mat under the aquarium to release tension in the glass and to avoid damage by uneven surfaces.
It will filter small particles out of the water. Also some bacteria will live in the filter material that have an important role regarding the water quality. There are different types of filters: Internal filters that are installed directly into the aquarium. They are probably the easiest solution but are taking up quite some space and are not looking very nice in an aquascape environment. External filter have inlets and outlets in the aquarium and will normally stand somewhere near on or under the table. They are the type of choice for bigger aquariums and will keep out of sight whereas the inlets and outlets are often nice to look at and bring some movement into the water which is a healthy addition. The compromise between these two filter types is the hang on filter which I am using for my aquariums. They hang on one of the sides of the aquarium walls, most likely hidden on the back side. They have a small tube into the water and an outlet above the water level. They do not need much space and are perfectly fine for aquariums up to 60 liters. They also add some movement to the water surface which will remove unwanted particles and bacteria here.
The next component is the light source. It is important for the plants to grow and get a nice and healthy color. LED lights are the most common choice today since they are flexible, long living and energy saving. There are many different types that are installed directly on the aquarium or hanging above it. You should connect the lights to a timer clock to simulate a day/night cycle. A common rule is to have 6–8 hours of direct light per day. Too much light can damage your plants and also lead to the growth of algae that don’t look nice in the aquarium. Not enough light and your plants won’t grow and loose color. You have to find the right amount by trying different settings since the amount of light needed is depending heavily on the amount and type of plants in the aquarium.
The CO2 system is not absolutely necessary, especially if you only have a few simple plants in your aquarium. But it will help you to achieve much better colors and healthier plants. I would absolutely recommend it. CO2 is needed by the plants to breathe. There are always small amounts of CO2 in the water that comes from the surrounding environment. Additional CO2 is provided in gas bottles. The bottles are connected to CO2 diffusors in the aquarium below the water level that will distribute the gas in tiny bubbles so it can be absorbed by the water. There are special CO2 systems for nano aquariums that have a tiny bottle that has to be changed roughly every month depending on the size of the aquarium. If you use an external water filter, you can also infuse the CO2 directly into the water flow as seen in the image below which will make the diffusor in the aquarium obsolete. If you have bigger or multiple tanks you might want to install a refillable CO2 bottle which is much bigger and heavier and has to be refilled at a local provider. The CO2 system should also have an overnight shutdown installed since the CO2 can only be consumed by the plants when the LED light is switched on.
A refillable co2 cartridge system is more complex but way cheaper on the long run or in bigger setups with multiple tanksNo aquascape without water. If you are creating a sweetwater aquascape, you can usually use normal tap water as long as it doesn’t contain any chemicals like chlorine — which would be deadly for animals. Also avoid any kind of metal in your water or later in your tank. You should ask your local water provider when you are not sure about the water quality. There are water supplements that remove chlorine and other unwanted components from your water. When adding water to an aquarium with plants or animals, you should assure that it has the required temperature. Advanced aquascapers are often creating their own aquarium water using osmosis systems.