Most aquatic stores will have a variety of fish to choose from ranging from cold-water, temperate, freshwater, brackish and marine. You will be spoilt for choice! Some stores will stock more species of fish than others so if there is a particular one you are after, make sure to ring beforehand and check that they have it in stock. Please note that you will need to choose the correct species of fish based on your set up. A top tip is not to buy too many fish at once as your beneficial bacteria has only recently established in your tank and you risk causing a spike in harmful toxins. Add a little at a time so the filter can slowly adjust and keep up with all the waste that will be produced in the aquarium. This is where a lot of people go wrong and they wonder why the aquarium starts to look cloudy. This is caused by adding too many fish at once and often referred to as a bacterial bloom. Now that we have got that out of the way... here are a few of the most popular choices for beginners.
Most beginners tend to keep cold-water aquariums when they first begin their fish keeping journey. Some good beginner fish for cold-water aquariums are fancy goldfish. You can buy them in a range of different sizes, breeds and colours. They are very friendly and will often swim to the front of the aquarium as they learn to recognise the face of the owner. The first ever fish I brought home was a fancy goldfish, so I am probably a little bit biased. I think they make great pets as they have such big personalities and can live a a long time if they are looked after correctly. They do produce a lot of waste so make sure to have a good filtration system and a big tank for them. Anything below 100 litres is not sufficient. They grow very big! Make sure never to buy a common goldfish for your aquarium as they will grow far too big for your tank and are best suited for ponds. Weather Loaches are also a good choice and they are very hardy fish. Weather Loaches could also be safely kept with most temperate community fishes which is the next option...
Temperate fish are not cold-water fish, nor are they cast as tropical. These fish are quite happy in an un-heated aquarium located in a heated room but they are definitely unsuitable for a pond or an aquarium which is situated in a cold room. They are becoming increasingly popular as time goes by. Paradise fish and some species of Barbs, Minnows, Loaches and Goodeids make perfect residents for temperate tanks. In winter time when the temperature drops, you may have to add a heater to keep the temperature stable so bear that in mind when purchasing.
Tropical community aquariums are quite popular and they involve keeping several different species all in the same tank that will all (hopefully) get along. Many considerations need to be taken when setting up a 'community' aquarium. You don't want fish that are going to be aggressive, predatory, or that nip at the fins of other fish. You also want to consider what water level the fish prefer to swim and school. Lastly, keep in mind that water conditions, size, and compatibility must also be considered when choosing fish for your community tank. Popular community fish species include Tetras, Guppies, Danios, Rasboras, Dwarf Gouramis, Platys, Minnows, Ottocinclus, Bristlenose Catfish and Corydoras.
If a tropical community aquarium is not for you, some people prefer to keep things simple and have a species only tank. This is an aquarium that contains just one species of fish, be it an individual or a group. I have to admit, I am a big fan of species only tanks. Betta, Live-bearers, Discus and Cichlid tanks are a good example of this. There is nothing wrong with wanting a tank full of your favourite fish. I have many species only tanks and I find that the fish do much better for it. They are much happier, more likely to breed and aren't bothered by any other fish. Most aquarists like to keep Malawi Cichlids in a species only tank as they require a high PH unsuitable for most fish. They are available in a wide range of colours and look great in aquariums which are stocked full of them.
Marine aquariums are also a joy to stock, especially when adding your first fish. It is no secret that saltwater fish are much more difficult to keep than freshwater. Nothing worth having comes easy but you can make it a little easier by choosing to fill it with the best saltwater aquarium fish for beginners. One of the things that make Tangs a great choice for beginners is that they’re hardy and resilient as well as extremely beautiful and great to watch. The Watchman Goby is also a great choice as they are quite peaceful kept by themselves and not picky when it comes to diet. When you’re just starting out, having a hardy fish such as a Clownfish or Chalk Bass makes it a little easier to learn the ropes. The Firefish also has a great temperament for community tanks. They’re really fun to watch because they move really fast and like to hide in all sorts of places. Green Chromis also seem to be a popular choice as a great shoaling fish. I would be selling quite a few of these to marine keepers and they were forever in demand. All of these fish above will make an interesting addition to a beginning saltwater community.
Going to purchase your first fish is an exciting time. You will be overwhelmed with the amount of choice available. Please make sure to do the proper research needed beforehand. Try not to buy on impulse (which most people do), make sure to choose wisely and don't forget to acclimatise your fish properly when you bring them home. There is nothing more special than looking at your fish swim around in the underwater world that you have created especially for them. The hardest part is keeping them healthy and maintaining good aquarium maintenance so you can enjoy them for many years to come.