Incandescent lighting?

why wouldnt you want 75 over 10 gal.

Because of the maintenance and upkeep. Also if you slack off on anything the effects will come swiftly with everything going at such a high rate. Constant pruning or battling some type of algae because you missed a dose of ferts, or had to go on vacation.
 
some people can handle the work.

Ah yes, but as I said, things come up. People have to go places unplanned or planned and don't have the means to take care of a high maintenance tank, and there isn't always someone close to them who knows how to care for a tank. Especially not a tank that needs constant pruning and regular fertilization.
 
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