For an aquarist, with four dozen published aquarium articles, this is a famous and yet fallacious chart
It recommends swapping water when the bioload of the aquarium reaches its highest point of toxicity. In other words, maximum fish and invertebrate capacity. OK if you don't care about the livestock in your aquarium. If you do, and your aquatic pets can endure high ammonia and nitrIte cycles, you have to change 30 to 60% of your aquarium water BEFORE nitrAte gets high. If your beloved animals can only endure high ammonia, then you must change water BEFORE nitrItes rise. Instead of one big notch in levels 50 days later in theory, the aquarist actually has to change water every 12 and 24-days in practice.
Of course, this is for new aquariums, which are cycling their ammonia cycle. For new aquariums, the aquarist has to reduce ammonia, nitrite and nitrate levels every 12 and 24 days EVERY time an additional bioload, fish or invertebrate, is added to the system. Reduction can be accomplished with mechanical water changes, biological or chemical filtration. Established aquariums can handle a new, larger bioload without additional filtration, although many aquarists DO regularly clean their filtration devices, which refreshes them.
It recommends swapping water when the bioload of the aquarium reaches its highest point of toxicity. In other words, maximum fish and invertebrate capacity. OK if you don't care about the livestock in your aquarium. If you do, and your aquatic pets can endure high ammonia and nitrIte cycles, you have to change 30 to 60% of your aquarium water BEFORE nitrAte gets high. If your beloved animals can only endure high ammonia, then you must change water BEFORE nitrItes rise. Instead of one big notch in levels 50 days later in theory, the aquarist actually has to change water every 12 and 24-days in practice.
Of course, this is for new aquariums, which are cycling their ammonia cycle. For new aquariums, the aquarist has to reduce ammonia, nitrite and nitrate levels every 12 and 24 days EVERY time an additional bioload, fish or invertebrate, is added to the system. Reduction can be accomplished with mechanical water changes, biological or chemical filtration. Established aquariums can handle a new, larger bioload without additional filtration, although many aquarists DO regularly clean their filtration devices, which refreshes them.
