Intro
First of all, I'm not saying you have to stop keeping fish (although it would be great for the welfare of fish if you did). This is about RESPONSIBLE fishkeeping. Fishkeeping is an amazing hobby. However, the most important thing to think about is the welfare of the fish. Keeping fish in tiny 5 gallon tanks is NOT okay. Not even bettas. In small containers, the fish are cramped, and can't live a natural life. All fish excerete ammonia in waste, and it will quickly build up and kill the fish in a small tank. Plus, small tanks can't hold many fish. That's no fun! Basically, small fish like guppies and tetras need at least a 20 gallon tank. You can probably keep about 10 small fish in a 20 gal. Larger fish need larger tanks. Go to livaquaria.com for minimum tank sizes. All fish need filtration (goldfish need double), tropicals need heat, and plenty of hiding spaces are a must. You must test the water for ammonia, nitrate, nitrite, and P.H. weekly. Live plants are always good, and increase the amount of fish you can keep. This is because they absorb toxins, and airate the water. Live plants are also beautiful.
Bettas
It is common belief that bettas MUST be kept alone, and are perfectly happy being eaten away at by ammonia in cramped, filthy bowls. Bettas do NOT like these conditions and other fish would SURELY perish. Bettas hold on because they have a labyrinth organ, and breathe air. Some places say that bettas don't need to be fed, just put a plant in their tank. Bettas are carnivores and just starve. In truth, a betta needs a 20 gallon tank WITH friends. Female bettas can live with other community fish and female bettas, and males can live with other community fish. One gallon tanks are not enough. Get a 20 or forget about it. However, the trade in betta fish is cruel and inhumane. For more info, go here: http://blog.peta2.com/2011/06/dont-buy-bettas.html
Goldfish
Lets get something straight: these fish can NOT ever live in a bowl. Goldfish grow big. A fancy goldfish gets 8+ inches long. Comets? 2+ feet. Koi? Only for a pond. Too big for your 5 gallon tank! Goldfish also need double filtration because of thye high amounts of ammonia they produce. Very few other fish can live with them for this reason. Goldfish have no stomach, so they need 3-4 small (and I mean SMALL) meals a day. They really enjoy bloodworms and skinned peas. 3 fancy goldfish can live happily in a 20 gallon tank. 4-5 can live in a 30, and so on. Basically 2 more can live in each extra 10 gallons. A comet/common goldfish needs a 55 gallon tank (this holds 3), and you can add another fish for each 20 gallons extra. Goldfish will die in heated water. Don't keep them with tropicals, with the exception of black moors, who tolerate warm water. Go to project Carp-Face for info on why to never keep gf and how to help them!
P.S Those feeders are often sick, so they die easily. And goldfish are high-fat so they're bad food for larger animals. Gars and other big fish can eat frozen shrimp. Garter snakes can eat pinkys.
Tankbusters
Tankbusters are large fish who need 1,000+ gallons of water. Often times these fish are endangered or have special needs. Never, ever attempt to get them. Not even you, advanced aquarist, or guy with new 500 gallon tank. And don't just say "I'll get a bigger tank" or "I'll put them in my pond" because it'll be too late, and warm water fish can't live in coldwater ponds.
Fish to avoid AT ALL COSTS!!!!!!!!!!
Red belly pacu, gar and needle fish, arowana, red tailed catfish, plecostomus, Iridescant shark, paroon shark, pangasius catfish, arapaima, shovelnose catfish, tigerfish, sturgeon, paddlefish, saltwater batfish, bala sharks, and saltwater sharks.
Body disposal
Fish must be buried or cremated when dead. It is most respectful, and flushing can release bacteria into the enviroment and harm native species. Throwing carcasses away just makes more trash for landfills. End of story.
This is a disgusting peson who put 15 fish in a 2.5 gallon tank. This person must have a 30+ gallon tank, and control the algae.
This is why you don't get tankbusters!
Dumb person with fish he can't handle... bet the poor thing's dead.
