I know this thread is a bit old but if you haven't purchased one yet, here's my experience. The reactor you're looking at is more for the control of phosphates or running carbon, not reducing nitrates. If you're having algae problems or just are just running higher po4 levels, it would still be a good purchase
Many times, the best way to reduce nitrates is through good husbandry. Watch the amount of food you feed and keep up with your water changes. My experience has been that these 2 actions will solve 90% of the NO3 problems most of us run into. There are also the natural methods of DSBs and macro algae. There is controversy as to whether these work but I have a 75g with about 500 heads of NPS corals in it and 2 clowns. It has a 4" sand bed in the DT and about 4.5" of mud and sand in the 'fuge along with rock and macro algaes. The coral feedings result in a massive amount of waste as if they don't catch it, it lands in the sand. I feed that tank the equivelent of 2 cubes of mysis each night. The highest the no3 has ever risen to is 2.5, with a Salifert test kit. My 135 has 7 fish, a very shallow sand bed in the DT and fuge (with macro as well). I average about 1/2 a cube of mysis or the equivelent, per day, and the no3 in that tank will often hit 5. I have to believe the refugium and dt setup in the smaller tank, along with weekly 20% water changes, are the reason for the low nutrient levels
Both tanks run dual reactors, for Po4 control, btw