This page will help you understand where piranhas come from, and what water conditions they live in.
Piranha, correctly pronounced (pee-ran-ya) come from the Amazon region and several of it's tributaries. The piranhas that are considered dangerous thrive in and around the river systems of the Rio Sao Francisco, Paraguay-Parana, Amazon, and Orinoco sytems. If ya don't know where that is, just pop out an atlas and look in and around the Brazilian area (South America).
The varying water conditions in which the piranha thrive can be describes as clearwater, whitewater, and blackwater:
Clearwater rivers consist of shallow, acidic rivers that are similiar to the rocky bottomed streams found in the Rocky, or Appalacian mountains where one might go to fish trout; the main difference being that the waters of South American are generally much warmer!
Whitewater rivers are murky rivers that contain a lot of sediment and are generally rich in nutrients. The whitewater rivers contain the most piranha species and is therefore the ideal environment for piranha's in the home.
Blackwater rivers are aply named "blackwater" because of the many decomposing leaves and other materials in the river which tend to give the river a "black" appearance.
This the the most common of the dangerous piranha species: it's scientific name is Serrasalmus nattereri, more commonly referred to as the "Red-bellied piranha". It exists in all 3 river conditions.
The rivers of the Amazon region generally don't fluctuate in temperature much. The lowest temperature in a typical environment would drop to around 73 degrees F. On the same token, the hottest that the same environment would get would be around 85 degrees farenheit.
Therefore, as one might expect, piranha don't like temperature fluctuations in their water! In the home aquarium, one must make sure that they can maintain a temperature of around 79 degree F for their piranha. Any loss of power during the winter could spell fate for the heat-dependent piranha!
Piranha's do have one more requirement in water, although this one is a little more flexible:
The water of the piranha aquarium should be slightly acidic. A pH of around 6.5 is the best with a hardness of 10 DH. For those of you who don't have any idea about what I just said, your local hobby store has kits and chemicals which you can use to test and maintain this important balance.
O.k. I'm through with the boring scientific stuff on this page, don't forget to check out more important info on the other pages.