Hi Zola and Welcome to TFF!
You have stumbled on to a really serious hobbyist forum full of many people with decades of experience in many different areas of the hobby. As a newcomer the things you read here may at first seem strange. But what happens here is that you can receive advice to help you do things as if you had been in the hobby for years.
You will probably be able to detect the frustration in the posts of our members. We see sometimes dozens of new threads from beginners each month and hear the same story over and over. Your story so far reads like a classic case, so the members are concerned to see you headed for many of the potential troubles they've helped with so often.
When fish respire (bring water through their gills) they take in oxygen and give off carbon dioxide, but they also directly give off ammonia(NH3). The amount of ammonia is small, but it is very steady and builds up quickly. Ammonia is a poison to fish. Excess fish food, fish waste and plant debris all break down in the tank to create more... ammonia! In nature, ammonia is carried away by thousands upon thousands of gallons of water but unfortunately in our tanks even tiny amounts of it can cause permanent gill damage and then death.
As hobbyists, we learn to grow two species of bacteria in our filters, the first of which belongs to the Nitrosomonas species and can process ammonia(NH3) into nitrite(NO2). Nitrite(NO2) is also a deadly poison to fish. Even in tiny amounts it causes suffocation, leading to permanent nerve and brain damage or death. The second species of bacteria we grow, Nitrospira, can process nitrite(NO2) into a third substance, nitrate(NO3), which is not nearly as deadly and can be removed during our weekly water changes.
The two wonderful species of bacteria that help us are very, very slow growers and until they are grown in sufficient quantities, we are left providing manual filtration to keep our fish alive and healthy, by means of frequent (usually daily) significant water changes, unless we have prepared a fully-functioning "biofilter" of live bacteria ahead of time. In recent years, the scientists that study fish have learned that fish do not initially show symptoms when they first begin receiving permanent damage from these poisons, so we've learned more about the beginnings of this process. Eventually, of course one begins to see symptoms, disease or death if the hobbyist is unable to control the poisons.
The problem for the retail pet industry is that any sort of description of this sort of information is either beyond the grasp of the newly interested parent or hobbyist or quickly drives them to reconsider their plans. So the typical pattern the shops fall in to ease the newcomer past this rough period by taking advantage of the inital lack of symptoms and by readily selling new fish for those that die. Eventually the tanks cycles and everyone involved tries to forget the fish that died.
Experienced hobbyists over time gain lots of knowledge about "biofilters" and realize that none of that startup trouble was necessary. This is what they hope to communicate to newcomers/beginners to the hobby. Regardless, now that you have fish in a non-filtered tank, you are in what we call a Fish-In Cycling Situation and we have experience helping people get through this, often with their fish alive. The baseline article for this is called Fish-In Cycling and is also in the Beginners Resource Center.
Good luck and I hope this will be the beginning of an enjoyable stay in the hobby!
~~waterdrop~~
/www.fishforums.net/index.php?/topic/277264-beginners-resource-center/
