First of all the 1" per gallon rule only applies to 1-3" fish - anything larger and it fails miserably - but that's rarely mentioned.
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All due respect to Tom Barr, but I'm a fishkeeper that uses plants to aid in water purification. Barr's EI method is focused on growing plants fast with lots of ferts, light, CO2, and huge weekly water changes... I just don't see how loading up a tank with chemical ferts is all that good for fish. As everything in the water gets into the fish through osmosis. Sure, it may be great for plants, but at what cost to fish?
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AND, all due respect to Dianna Walstad, but her method only works with a very heavily planted tank with VERY FEW fish, unlike what most hobbyists would want or have. (I also feel a dirt tank is more trouble than it's worth and 1-2" of 'dirt' in an aquarium is going to loose any nutrient value it brought to the party very quickly to become nearly inert anyway.)
[end rant]