Some fish are just too much of a hassle to keep in an aquarium. Aquarium enthusiasts tend to focus on how fish look when selecting fish for their tank, but there are definitely some fish that most aquarium owners should avoid. Here’s a list of some fish you’ll likely want to skip when planning your future aquarium:
African Cichlid (for a community aquarium)—a good looking fish, but way too aggressive. They not only fight among themselves, but also with every other fish in the tank, so you may just want to avoid the hassle. Be extra careful if you’re considering putting these in a tank that already has a stable population. They may very well destroy the entire thing!
Arowanas—there are two problems with these fish. The first is that they get sold to unsuspecting aquarium owners who don’t know that these fish will grow so large that they will likely take over the aquarium. The second is that in order to grow, this fish will try to eat everything else in the tank.
Koi—people love to see koi fish in ponds and gardens around. The thing is, that’s where they belong. Koi get too big, and need too much water to themselves: around 100 gallons per fish.
Discus—these fish look awesome, but have very strict temperature and water change requirements. If you don’t have a professional aquarium servicer, and prefer to do things yourself, you may want to avoid this fish because of the extra care you’ll need to put into every aquarium maintenance activity.
As you can see, there’s a common theme here—fish that are a bad idea to have in your aquarium tend to fall into one of two camps: they are either aggressive to the other inhabitants, or grow so big that they start to present problems in the confined space of an aquarium.
So, make the smart choice and don’t invest in any fish that will present you with headaches. Most importantly, consult your aquarium installer or servicer, and they should be able to tell you if the fish you’re planning on using will work well for your chosen aquarium size and setup.