Well is a great Big unknown for you. But others here have come on their posts with levels below 10 and have used the D2 and showed little or no progress for them.
So everyone is different...why look for the answer when D3 works so well anyway? No one is likely to do a study against a better product IMO.
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All truths are easy to understand once they are discovered; the point is to discover them.-- Galileo Galilei
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Weezie looking at petunias 8.25.2017
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