There’s no one performing water changes on large bodies of water like oceans, lakes, and rivers, yet fish are still able to live in them.
There’s no one performing water changes on large bodies of water like oceans, lakes, and rivers, yet fish are still able to live in them. How can this be? For the most part, oceans have such a vast amount of water that the nitrate levels are probably insignificant. Meanwhile, freshwater lakes and rivers usually have plants growing in or on the edges of the land surrounding them. Nitrates are one of the nutrients that plants need to grow, so they uptake it through their roots and out of these bodies of water, thereby cleaning the water. There’s also a denitrification process that can happen in these natural sources for aquatic life that we will go more into later.