In the visible light communication (VLC) system, the discrete multitone modulation (DMT) is one of the alternative efficient modulation schemes and the bit-power distribution among related carriers is crucial to the final channel capacity. In the paper, the channel capacity in Krongold algorithm is compared with the upper bound and the lower bound. The former is in the water-filling principle and the later is in the traditional average allocation in bits and power. It is worth mentioning that our work aims at applying these techniques to VLC.