It happens to most first-time fish keepers.
They run to the fish store, pick out the best looking fish they can find, and get all the stuff they need for their aquarium. Then they fill up their tanks and plop their fish in the water. Over the course of the next week, their fish aren’t looking so good. Then all of a sudden, BAM! All of their Kenyi Cichlids start getting picked off by Death.
Luckily, there is an explanation. And here it is: ammonia and nitrite is toxic to fish.
You see, keeping fish in an aquarium produces ammonia. If a fish is placed in a brand new aquarium, the aquarium wont be equip with the ability to convert that ammonia into a less harmful chemical. And that’s why they die. Because they get poisoned by the ammonia.
To avoid the whole fiasco, you have to understand a little something called the Nitrogen Cycle.
After ammonia is produced in an aquarium, a bacteria that is naturally found in water (a bacteria that consumes ammonia and produces nitrite) reproduces itself to form a large enough colony to convert all of the ammonia into nitrite.
As the concentration of nitrite increases, the same thing happens to the nitrite that happened to the ammonia. A colony of bacteria that converts nitrite into nitrate forms in large numbers.
It takes about 1 week to several months, depending on your technique, but that’s about it. That’s the Nitrogen Cycle.
When an aquarium reaches a point where it can convert all of the ammonia and nitrite being produced in an aquarium to nitrate before they reach harmful concentrations, it is referred to as Cycled – it has completed the Nitrogen Cycle – it is safe for fish.
So before you ever place a fish into an aquarium from now on, ensure it has completed it’s Nitrogen Cycle first. To do so, increase your aquariums ammonia concentration to 2ppm with Ammonium Chloride. If after 24 hours, your aquarium has no trace of ammonia or nitrite, you can rest assured that it’s Cycled. You just need to perform a partial water change and your aquarium is ready for fish.