Planted Tank Obsessed
Join Date: Dec 2010
Location: Binbrook, Ontario, Canada
you could add sand as a cap to the top layer of existing substrate. Over time it will filter down into the substrate below and fill up the spaces. Put wet sand into a cup and gently pour it out onto the substrate with the water still in the tank. Just wash/rinse the sand you use really well. No need to remove the existing substrate.