We have a small 10 gallon fish tank which we keep stocked with fish who die on a fairly regular basis. I am sure my brother would scold me for not changing the water often enough. I actually think it is more a matter of over crowding as we (try to) do water changes on an almost weekly basis.
We have a Plecostomus to keep the green furry stuff from overwhelming the tank. We have a Catfish to get what falls to the bottom. We have a handful of various Tetras to entertain us for minutes at a time. In the tank I have 4 different live plants (I always seem to kill the plastic ones...). I have purchased all these live things and nothing else.
Where the heck did this snail come from?
The next case will be the case of the Appearing Trout after one of the kids put the fish they catch into the tank....