Gasp!! An affordable sulphur denitrator at last!! OMG. Reef Depot is selling units of Deltec's NF-509 denitrators, and it really is going at half the price I expected! Gasp!! Oh dear. Oh dear. I need the $. Totally dared not measure the NO3 levels in the tank, the water's been running entirely off no changes, no additives and minimal skimming for the last 2 months during the exams. Definitely need this piece of equipment to make my job easier.