Do water plants put disolved oxygen in the water?
They do – to a degree. There are some experts that even keep fish with just plants and no filters. But this is a very delicate situation, and you have to consider how you stock your aquarium very carefully. In this type of natural filtration tank, you can’t keep nearly as many fish as if you did have a filter – in fact, these tanks have a tendency to look very understocked. And to put out enough oxygen to keep your fish alive, you would need to have the aquarium almost fully planted – the back 2/3, and along the the sides, with just an open area in the front for the fish to swim. So unless you have very active fish, you may not see the as often, as they’ll be in the plants. To make this work, you’d need a fairly good light (remember oxygen is produced through photosynthesis). Putting the tank in front of a window can raise the light level, but if the sun would hit the tank directly, it can also raise the water temperature. As the water gets warmer, it holds less oxygen. You would also
