Söchting Oxydators - Make Your Own Solution
Here is a link to where you can buy the proper "food" grade 35% Hydrogen Peroxide - which you must "dilute" with pure distilled water (or RO Water) to achieve the desired concentration as follow:
1 part 35% Hydrogen Peroxide to 6 parts distilled water yields the recommended 6% solution.
For example: 60ml of 35% food grade Hydrogen peroxide plus 360ml of distilled water = 420ml of 6% Hydrogen Peroxide.
A 1-to-2 ratio of 35% food grade Hydrogen Peroxide to distilled water would yield a 12% Hydrogen peroxide solution.
A 1-to-3 ratio of 35% food grade Hydrogen Peroxide to distilled water would yield a 9% Hydrogen peroxide solution.
You can adjust the % food grade Hydrogen Peroxide as desired to accommodate the rate at which oxygen is dispensed from the Söchting Oxydator into the aquarium.