How often should I be removing fish poop from the bottom of my tank?

[itiwhetu]

The idea that in the wild the crap gets washed away is not exactly true. All that happens is that the crap gets washed down stream. So high in the mountains very little crap is getting washed passed, towards the ocean all the crap from all the fish up stream is getting washed passed you. Nature does water changes just like we do, through rain. But if it doesn't rain then the concentrations of fish poo get higher and higher. Nature doesn't vacuum it out.

 

[Bruce Leyland-Jones]

The idea that in the wild the crap gets washed away is not exactly true. All that happens is that the crap gets washed down stream. So high in the mountains very little crap is getting washed passed, towards the ocean all the crap from all the fish up stream is getting washed passed you. Nature does water changes just like we do, through rain. But if it doesn't rain then the concentrations of fish poo get higher and higher. Nature doesn't vacuum it out.

As long as the water's flowing, it's a continual water change scenario and toxins all move away with the current. There's also the important element of dilution, as only a very fortunate few of us may have a tank that contains anything close to the amount of water even a small stream will have.
Obviously, when drought hits and the water flow becomes sluggish or even stops altogether, problems quickly arise, usually characterised by a marked die-off of the animal population and an increase in less-than beneficial bacteria, including blue-green algaes.

 

[itiwhetu]

As long as the water's flowing, it's a continual water change scenario and toxins all move away with the current. There's also the important element of dilution, as only a very fortunate few of us may have a tank that contains anything close to the amount of water even a small stream will have.
Obviously, when drought hits and the water flow becomes sluggish or even stops altogether, problems quickly arise, usually characterised by a marked die-off of the animal population and an increase in less-than beneficial bacteria, including blue-green algaes.

But the toxins that are moving away are just going pass the next group of fish and so on and so on. They are not being removed from the stream or river.

 

[Bruce Leyland-Jones]

But the toxins that are moving away are just going pass the next group of fish and so on and so on. They are not being removed from the stream or river.

Dilution.
Water courses generally get bigger as they move towards the sea, though I take your point. Consider what happens to the animal population of a stream that experiences a toxic/agricultural waste spillage. The toxins pour over the fish and kill them. Then we get corpses floating in relatively clean water. This is why it is often so difficult to identify the culprit for such contamination.