Here's a tip if you want to save some real money over buying liquid Hydrogen Peroxide. Buy Sodium Percarbonate.
"Sodium percarbonate is very neat stuff. It is a powder that releases hydrogen peroxide, and it is very concentrated.
To be complete, sodium percarbonate releases hydrogen peroxide and soda ash. As we know, hydrogen peroxide breaks down into oxygen and water. As you may expect, then, sodium percarbonate breaks down into oxygen, water, and soda ash."
http://www.using-hydrogen-peroxide.com/sodium-percarbonate.html
You can go to your local dollar store and pick-up some of their dry chlorine-free bleach. Mine sells it 1#/$1, comes with its own scoop inside.
http://www.lastotallyawesome.com/html/Products_Household_OxygenCleaner.html
Or, it sounds like you can buy this cheap and in bulk at pool supply shops, which might make me trust it a bit more than a dollar store product.
Buying it dry is much more economical than buying hydrogen peroxide liquid at Walmart or such, and you can increase the strength easily.
I use this at pretty decent strength, and its surprisingly strong. You'd have a hard time getting an equivelent strength like 35% Hydrogen Peroxide shipped to you as its considered a hazardous material. But you can make your own easily.
Anyone know pool store pricing? Wonder if HD or Lowes carries something.