All the tanks you see there are shop aquariums and the only reason they can get away with doing that is because the numbers in the tank are always changing ( getting lower one would hope for the shop owner ). I would never recomend this to be done in the home aquaria..What we shave to appreciate is that shop fish are usually only there short term, where as our home aquariums are long term which really does change the situation...
So, answer is no...
Niko