We describe a symbol detection scheme for multilevel two dimensional optical storage (TwoDOS), where the channel is characterized by non-linear inter symbol interference and the dominant source of noise is media noise, both of which are characterized accurately by a non-linear channel model. Signal waveforms from the channel model are described as an explicit function of the channel symbols. Based on the non-linear model including media noise, we design and develop a practical symbol detection scheme for multilevel TwoDOS. This low complexity detection scheme is simulated for multilevel data for discs with different densities in the presence of media noise. Our proposed detection scheme exploits the properties of the 2D data format on the disc and is flexible enough to accommodate performance and complexity restrictions.