LSM Media (Live Sulfur Media) from Caribsea. 1 gallon. Here is a pure granular elemental sulfur, with sulfur reducing bacteria right on it. This product can be used in a number of ways, and accomplishes the same job of nitrate reduction as our NO-NO3. This product is ideal for dual chamber reactors, using our A.R.M. in one reactor and placing the L.S.M. in another. This results in a system that delivers elevated calcium, and reduced nitrates.