Fundamentals of Fish

In preparation for setting up a 20 gallon fish tank, I've been reading a lot about fish. I thought I share a smattering of that info. Here's the rundown: I learned a lot about different fish types so now I can identify the typical tropical fish like barbs, tetras, gouramis and the like. I've also learned that different types of fish have different swimming behaviors (surface, middle, bottom). And then there is the oft quoted rule of thumb whereby you shouldn't have more than 1" of fish per gallon of water. It's just a mere guideline since decor will occupy at least a gallon of the tank's capacity. Plus, many small fish is not the same as a few large fish. And finally, I have learned that new tanks need to be cycled before bacterial levels are sufficient to process the fish wastes. So much to think about when it comes to setting up the equipment and then populating the tank!