I would argue that this is the only way to go for nitrate reduction on large systems. I initially went with two Phosban reactors to test the concept for myself, before committing to a larger unit
Seeing the test reading of zero nitrates out of the reactor was like magic after struggling with nitrates for a year (we overfeed and that's not going to change ... so we know the source). Doing religious weekly 50 gallon water changes for 2 months steady still only took nitrates from 40 ppm down to 30 ppm, and skipping one week would put us back to the start.
With a DIY reactor based on the Phosban design (two 6" x 36" cylinders), we took the nitrates to zero in 4 weeks on our 500 gallon FO system.
The rotten egg smell can create the occassional "Annacis Island"
as my wife calls it, but can be masked with some burning oils until the flow rate is corrected (too low of a flow rate creates H2S). For those who've driven over the Alex Fraser bridge on a muggy summer day, you will understand the reference to Annacis Island
