My personal opinion on stocking is like saying Honesty is the Best Policy. Everyone knows that. Understocking is the best policy. We all know that, and of course, we all know that understocking is the safe way to go, but as previously stated, each tank is different, so going by the inch per gallon rule does not make a whole lot of sense. Going by the less than an inch to gallon makes more sense. Bottom line to me is that as long as your water parameters are staying good, then you are ok. That may take more water changes for some folks who are slightly overstocked, but that is ok if you keep up with it. How do you sell that to people new to the hobby? Difficult. If they really care, then they will ask and learn. If they do not really care, fish will die, but it has been my experience that people who do not really care, or have a deep interest in fish keeping, will pretty quickly give it up after a few failures.