Quote:
Originally Posted by Lumpy
Very cool looking fish... especially the Jack Dempsey! 
I wanted to go w/ Cichlids, but Gonzo wanted a Red-Tailed Shark, so we went w/ community fish. Now the Shark bullies everyone in the tank, including our Clown Loach. The only fish he doesn't mess w/ is our Common Pleco. That guy is a monster, measuring around 14"!
Oh, and I  at your snail pushing the golf ball... too funny!! |
Most cichlids would probably be OK in the same tank as your shark, as long as there's enough room.
Achieving peace in your aquarium can be one of the most difficult aspects of "fishkeeping"(
)...
You can't really just go and buy a bunch of purtty fish and throw them together. Which I learned the hard way when starting out. And it's not as fun when you have just one type of fish in the tank. It takes a lot of research and practice to find the right mix of different fish. A few tips I've learned in achieving aquarium peace:
Carefully research what fish you want to see what type of temperament to expect. Some are very aggressive and don't play well with others. Some require a certain tank size in order to feel comfortable.
Don't overcrowd your tank. Common mistake that can lead to over aggression. Don't buy fish that will eventually outgrow your tank. It's always a good idea to have some "hiding spots" in the tank too, where smaller fish can escape to.
Be very careful about having multiple fish of the same color/shape. They'll be more aggressive toward fish that look like them. Having only one of each species of fish is a good way to encourage peace, although that doesn't always work. And some fish do much much better in pairs.
When possible, learn how to determine the sex of your fish. There's a number of ways to do this if you know what to look for. This also helps in having as bright and beautiful of fish as possible, as males normally have considerably more color than females. Females tend to be more territorial as well, and can aggressively defend spots in the tank when it's breeding time.