Pomacea Canaliculata

any tips on caring for a Pomacea Canaliculata? i have had mine for about a year and a half... and it is about the size of a small tennis ball. However...it's shell seems to be eroding... he is in a 12gal tank with a PH of 6.5-7.0

Have a look here: http://www.applesnail.net/. This site shoud have all the info you'll need.