This looks like a well-planted up community fish tank but don't be deceived by its appearance. It is actually a fish spa therapy shop located at 333 Somerset. Some of the fishes look kind of big and I find it quite uncomfortable watching people, mostly tourists I guess, sitting on the ledge with their legs immersed in this tank.
Within a matter of seconds, the fishes would descend on the legs and start to do their job of removing dead skin from the legs. Some women withdrew their legs because of the ticklish feeling, I suppose? This form of therapy is said to aid in skin renewal but I have also read articles claiming that such treatment may pass on fungal diseases. Hence, I dare not try it myself.
I read that this is also very popular in Qian Hu fish farm in Lim Chu Kang.