Here we are joined by my two African dwarf frogs; Trevor and Chocolate.
I’m gonna cover why small, filterless tanks/bowls don’t work. I’m using frogs as an example, but this goes for fish as well. Space: It’s not enough space for active, social frogs in a .5 - 1 gallon cube or bowl, they need a hide, plant cover, and space to swim around and explore. Amphibians in particular excrete a lot of ammonia, which builds up quickly in an enclosed space, even if you have beneficial bacteria living in your substrate. Amphibians are especially susceptible to toxins in the water (same with scaleless fish), so it’s especially important to keep the water clean for them (and all fish, no animal should have to live in filth). Filtration: yes, in a mature healthy tank, you’ll oftentimes get beneficial bacteria in the substrate, and sometimes you may be able to buy “live filtration” to keep in filterless tanks, the producers want to convince you that it’ll keep the tank squeaky clean for you, just like a powered filter! Well, no. Beneficial bacteria that resides in your filter needs to go through all the water in your tank to suck up the ammonia, filters filter all the water in a tank multiple times an hour. The bacteria sucks up the ammonia, and converts it to nitrites, which is less toxic but still bad, so another bacteria converts that into nitrates, which are harmful in large amounts, but are kept at safe levels with weekly water changes in a cycled, filtered, appropriately stocked aquarium. Filters also have an important role in causing surface tension in the water, oxygenating it (you can also use a bubbler). It’s true, frogs breath surface air, so they don’t need oxygenated water, right? Wrong. (Fish need oxygenated water to breath, gouramis and bettas have a labyrinth organ which means they can breath surface air, but they cannot survive on this method for very long at all) Beneficial bacteria is aerobic (needs oxygen), so for healthy beneficial bacteria to thrive and do it’s job, you need surface tension. Bad bacteria, however, is anaerobic (no oxygen), which if gets into the water column can be dangerous to all aquatics. *keep reading in my next post*