no need to feed 2-3 times daily, once in the evening is fine
AOD is not kidding, it is healthier to feed them very sparingly. Even skipping a day altogether every now and then is a better simulation of their natural world. Plus, less leftover food produces less ammonia and that is going to be a big issue for you because of not knowing about cycling.
Welcome to the forum WadsleyOwl. I too am helping my son, an 11-year-old, to set up a tropical tank. You can not imagine how lucky you are to have stumbled across this forum. I did a lot of comparing and this forum is one of the most active and informative and just generally nice places out there. If you have the time and inclination, you can gain knowledge and skills here that are many times more valuable than the equipment you buy or the advice you would ever get from a local fish store.
The "cycling" thing they are talking about is crucial. Without knowing it you are in the midst of what is known as a "fish-in" cycle. This is because the filter you probably set up with your aquarium was not really a ready-to-run device as many think it must be, instead it is a raw hardware device which needs to have two bacterial colonies grown inside it before it will become the tool you need, called a "bio-filter." The job of the bio-filter function of your filter is to process ammonia and nitrite down to zero parts per million in your water and then leave you with nitrates in the water which are somewhat less harmful to the fish than these first two poisons. You can then remove the nitrates with water changes.
Growing these two bacterial populations takes on average 21 days, but it can be as short as 3 days or as long as 70 days perhaps. Fish respiration, fish waste, excess food and dead plant material all break down into ammonia. The first bacterial population (almost entirely anchored to the media in the filter) feeds on this ammonia and produces nitrite (NO2). The second population (a different species) feeds on the nitrites and produces nitrates (NO3) which then are easily removed via these water changes, typically 20% (only a few litres for you) once a week.
If you had a "cycled" filter all this normal description would be easy. Unfortunately (and it happens to the majority of people we talk with) you had no way of knowing (the truth is so bad for business that stores conveniently tend to forget this info whenever they are exposed to it..) and so have fish in your tank. The fish are respiring and processing food 24/7 and ammonia is being produced with nowhere to go. This ammonia will burn their gills and injure them. Once a little ammonia begins to be processed into nitrites (NO2), that substance will get into their bloodstreams and compete with oxygen on the blood cells, thus causing suffocation.
OK, enough of the bad-sounding stuff: Your course of action is easy. You need to obtain a liquid-based test kit if you don't already have one. Throw out those test strips if that's what you brought home. The Nutrafin or API kits are good, many here use the API Freshwater Master Test Kit. Have your son pick out a notebook at the stationary store and start a daily log of activities and test results. Have your son learn to perform all the tests - its like a chemistry set, its fun. You will need to watch and pay attention to ammonia, nitrite and pH the most at first. You will need to read as many articles as you can here and then start following the other beginner threads - lots of great info to learn and the articles can't teach it all.
You will have to learn about water change techniques immediately because only water changes will keep those fish alive in the uncycled aquarium. By changing water and testing for the presence of any ammonia or nitrite, you will keep the fish alive and the filter will be slowly cycling. Your tests will enable you to follow the progress of the cycling process. Your son can learn about the Nitrogen Cycle (there are some picture charts on wikipedia.) Its a great introductory tool for environmental science and fascinating for you as the parent.
OK, hope this helps a little and makes the information in the articles more personal. The many experienced members here will answer your questions and you'll see me and my son from time to time asking ours I expect, so good luck!
~~waterdrop~~
ps. Post up your test results for your tap water (good first learning test) and for your tank here along with info on days since tank start, tank size, any chemicals being put in (shouldn't be any probably) and your questions about water changes or anything else -- they will help you.
