The original page is gone but the link still exists on several pages including links at RIU:
http://www.house-garden.us/articles/why-have-the-npk-numbers-changed-on-house-garden-products/
Can't find that original doc anymore, no cached version either. The following article is probably derived from it:
"Why are we not seeing a guaranteed analysis on the new H&G bottles?
A guaranteed analysis numbers are representative of the amount or percentage of a certain element per unit of volume. These percentages are obtained through certifying agencies that do not always use the same instrumentation, the same scale, and the same procedure. To complicate things further, every state began to do their own testing a couple of years ago without standardizing the testing – it is up to whichever independent lab they are using to determine these numbers.
So in an effort to prevent any unnecessary misunderstanding regarding a guaranteed analysis, H&G decided to use the MINIMUM guaranteed analysis numbers instead. Little did they know it would cause so much confusion. [...] "
http://sdhydroponics.com/resources/articles/gardening/why-have-the-npk-numbers-changed-on-house-garden-products
Not sure if it's even related to the NPK difference of Drip Clean in particular... Shop near me was closed, will have to go Monday and hopefully will have a reply from H&G by then as well.
Perhaps a moderator can change this thread's title to Drip Clean NPK ratio and remove the OP's post
- we got enough threads on flushing already...
"Do not always use the same scale" isn't just the case here. For example, yours could be a % of the bottle's contents, mine could be a % of the contents that isn't water? But that wouldn't explain the ratio difference...