Pre-determined Quantities

With help of our support team, we can add some custom code on your theme files to force quantities on multiples of X, all you'd need to do, is to tag your product(s) as "multiX", where X is the minimum order you want to allow for the product. 

E.g adding the tag "multi5" will allow only quantities multiple of 5: 5, 10, 15, 20, ... etc.