What fish cannot you have in a BiOrb or BiUbe aquarium?
There are a number of factors that determine which fish and how many you can have in any aquarium, and there is a lot of conflicting information on the internet. Some sources claim it is the volume of the tank, some say it is the surface area of the water, some say it is the physical dimensions of the tank, and some say it depends on the filtration system. To some extent, all of these factors influence the number and type of fish you can have in an aquarium.
BiOrb and biUbe have another factor that must be taken into account. Instead of the standard gravel used on the bottom of fish tanks, these tanks have “ceramic media.” This ceramic medium looks like gravel and has a diameter of between 10 mm and 18 mm. It is very porous, which allows the bacteria necessary for the biological element of the filter system to grow. It is essential for the functioning of the biOrb and biUbe tank and must not be removed.
Why does this affect the fish I may have?
The ceramic medium, compared to standard aquarium gravel, is very sharp, and this makes it unsuitable for bottom-feeding fish. The vast majority of bottom-feeding fish have a soft belly, which does not adapt well to coarse ceramic media.
What kinds of fish feed on the bottom?
In general, loaches and catfish feed on the bottom. If you are in a pet store and there are no labels on the tanks, it is fairly easy to identify bottom feeding fish, even if they are not on the bottom. The vast majority of bottom-feeding fish will have their mouths tilted downward. Even if a fish is stuck to the side of the aquarium, they would still be classified as bottom feeding fish and are not suitable for a biUbe or biOrb. If the reason you want to have a catfish or loach in your tank was to add something other than “normal” fish, maybe you could consider buying shrimp. There are many different types; cherry shrimp, ghost shrimp, amano shrimp … They are fascinating to watch, they do a lot of cleaning and are an excellent addition to any aquarium.
Is there something else that I can’t keep?
Even the largest biOrb isn’t large by normal standards, so keeping a fish in it that will eventually grow to more than 1.5 inches (about 38mm) isn’t going to have a particularly happy life.