Sugar

Watched a program on artificial sweeteners the other week and they compared the amount of sweetener needed to replicate that of sugar in a fizzy drink and the difference was staggering. In an 8 gallon tank they needed about 10kg of sugar compared to a small bowl of sweetener (these figures may be completely wrong, just there to illustrate massive difference). They also tested brain activity when comparing sugar and sweetener and sugar triggered a "fulfillment or pleasure" receptor that the sweetener didn't, supposedly because sugar gives you energy where as sweetener doesn't.

Sweetner usually used is aspatame.Slow kill poison.