Fish food, as you can imagine, is a big topic with hobbyists, so you'll hear as many opinions as there are hobbyists probably. Personally I think you have to just start somewhere with something that you think is reasonably healthy and then learn and take tips from the forum and gradually experiment with making your fish's diet more varied and healthy. I've always thought TetraMin flakes were are decent starting place for beginners, the ones in the brown and yellow bottle, but there are probably plenty of other healthy flake choices out there. Always be cautious when introducing specialty foods, like frozen or live ones. Done correctly of course, they ultimately will provide the healthiest diet, but there can be details that are important: for instance, brine shrimp should be treated more like a "junk food" snack and only given occasionally and bloodworms should not be overfed as they can cause intestinal complications due to their rich nature. Anyway, good luck with your feeding! Its a lot of fun feeding tropicals!
I also agree that FHM's advice of getting in the habit of the weekly water change is essential. This is one of the core skills of the beginner hobby, right alongside understanding biofilters. Always use a gravel cleaning siphon for water changes and gradually work on your skill for deep cleaning the gravel or for cleaning the surface if you have sand as a substrate. Either way, a lot of debris you don't want will go out with the water that's being changed out and that's good. The percentage of water volume you change each week is something that you need to figure out over time. While you might start by changing 25% just because its a nice round number, it could be that a larger or smaller change would be best for your tank.
The nitrate(NO3) tests you perform can help you in narrowing in on the ideal percentage to change. NO3 should usually turn out to be between 5 and 20 ppm -above- whatever your source water ppm is. So if you use tap water as your source water and it has zero ppm nitrate and you are showing 10ppm nitrate(NO3) at your test at the end of the week then your water change percentage is quite good. If your tap water comes in at 10ppm nitrate and your tank tests at 40ppm then you're "adding" 30ppm from the various processes going on in your tank and that's a little high, so even though 40ppm is not a "bad" number for NO3, it still might tell you to perhaps make your water change percentage a little larger, to see if you could get your overall NO3 reading down to 30ppm.
Water changes are really about a lot more than nitrate(NO3) however, they also remove lots of heavy metals and organic substances that you might not want building up in your tank over time (since water that evaporates is pure water, other substances get left behind and build up over time.) So a good nitrate reading would never be an excuse not to do the weekly water change! We all have weekends when we can't do it, but if we understand its importance we'll be anxious to get back to it the next weekend.
~~waterdrop~~
