1/10th is not a bad estimate.
It's a simple mathematical relation actually. Length is a single dimension, volume is a cubic one. Therefore to see the change in volume, and consequently mass, of a fish you have to use the cube or cube root of the relative lengths. For instance a 2" fish is twice as long as a 1" fish. Twice as long so 2 cubed is 8. Assuming a similar body shape the 2" fish is 8 times as massive as the 1" fish. This is the big reason the "inches of fish" rule fails so spectacularly. I've been toying with a method to estimate stocking levels based off fish volume but it's far FAR more complicated than just saying "6 inches of fish in a six gallon tank" so I doubt it'd ever catch on.
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Last edited by Tyyrlym; 12-17-2008 at 02:23 PM..
Reason: Fine tuned wording on the math.
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