Yeh thats true, thats why you need to have a well established plant tank ebfore you add predators. When a planted tank is well established the roots are so deep and strong that they cannot be torn out. I specialize in planted tanks, espesh CO2 fed planted aquariums. I've grown and propagated every plant and coral i can get my hand on.
I'm sure he can live in that tank, but if i ever had a nice sized knife like that i would have a 5-6 foot tank, more than likley a 6ft tank with plently of plants and logs. But i just love the look of a planted tank more then the fish,

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