Good Luck with your aquarium - They can be a lot of fun.
Place a LOT of focus on your filtration system and it will literally run itself. Don't sit on water changes too long, vacuum your gravel - but dont' vacuum too much. Plecos are over - rated, they don't do as much as people think. With aggressive fish (cichlids), when you add a new member...change your landscape-ing, monitor the tank closely until they've learned to live together (3-5 days) -
I like saltwater tanks, but the maintenance can take away the fun factor - more testing, salt-buildup/etc...
Piranha's were fun, while they were little...very aggressive eaters, as they mature/grow they become less active. There were times when I dropped 6 feeder/fish in the tank and watched for about 45 minutes, and nada...the adult piranha did nothing. I'd walk out of the room grab a cold one...and when I returned, there were only 2 left, watched again for awhile....and nada. Strange feeders as adults, vicious little bastards when small.
There's definately more to keeping a tank then putting fish in some water and feeding them. To keep a well balanced aquarium one must do his homework. There are a lot of good tips in this thread - mix your tank water with the store water but not the store water with the tank water

...let me rephrase that, take a small tupperware container, fill 1/3 with your tank water, fill 1/3 with the store water, leave 1/3 empty...snap the lid on and float it in your tank for an hour (not too long - as your not oxygenating the water) - then scoop the fish out of the container into the tank, discard the tupperware water. Acrylic will disappoint you in the long run in my opinion. just my .02 -
Again - Good Luck and have fun with it.
P.S. - don't do what I did and drop a bluecrab in there......yellow tang appetizer followed by some clownfish pudding

...a free bluecrab cost me lots a money
