If you only keep LPS, your nitrate level is fine as is. If you do want to lower it, easiest way is to feed less. Water changes is kind of a band aid, but could work depending on volume removed/replaced. A fuge with macro algae and or a ATS (think that stands for auto turf scrubber) attacks NO3, but also helps a bit with PO4. Macro also is a safe haven for a lot of pods and other beneficial fauna. ATS runs the same principle but is suppose to grow algae faster, thus increasing the amount of export based on size. They do require maintenance. A SO4 reactor is good for only NO3, and doesn't lower PO4. Usually PO4 is an issue as well. The great thing about the sulfur reactor is it can be dialed in very precisely. only minor adjustments are needed over time and there is no maintenance. I have the output of mine, near the skimmer and don't worry about the PH issue as when it's a few drops a second, will not impact PH in my experience. Also 2 cups of media could reduce and keep a 400 gal tank in check for more than a year, so any small reactor will do. I do believe the recirculating aspect of a cal reactor, or a SO4 reactor helps. It's possible to have a single chamber type reactor work, but it takes longer to establish, and have to go slower on increasing the output. Hope this helps.