There are many ways to shock a tank and kill its inhabitants. A good maintenance schedule is not one of them.
Take a manufacturer's product ratings 'with a grain of salt' or however the expression goes.
Here is some good reading on nitrite and nitrate
Nitrite and the Reef Aquarium by Randy Holmes Farely
http://www.reefkeeping.com/issues/2005-06/rhf/index.php
Nitrate in the Reef Aquarium by Randy Holmes Farely
http://www.advancedaquarist.com/issu...t2003/chem.htm