Never used the DSM. For the 220, since I had my base substrate as organic soil, then capped with eco-complete, I had to drain and fill the monster (using a garden hose through the window) for a week to remove tannins and such that leached from the soil. I saved as much of the eco-complete water as I could in a container until after I planted, which was 8 days after inital substrate install and filling. Tons of plants were added and small water hyacinths as floaters to mop up excess nutrients. Sorry but I have no clue about DSM method. In the goldfish tank I did a swap out substate.