I just found this nitrate anion resin with this comment at the bottom of the page.
Intelifil (IF-SM-NIT010B) 10"X4.5" Big Blue Strong Anion Nitrate Removal Filter
https://www.amazon.com/Intelifil-IF...777739&sr=8-5&keywords=nitrate+removal+filter
"Using API liquid Nitrate test kit, my tap water shows 20 ppm before the filter and 0 ppm after the filter. It fits the big blue 10" filter just fine (10"x4-1/2"). There were no instructions included. The first 15-25 gallons were lightly yellow colored and foamy with a slight odor. Most filters have to be flush rinsed initially. After flushing, the water is clear and seems normal. No problems with my fresh water aquariums using 100% this water. It does lower the Total Alkalinity of the water, took mine from 120 ppm to 40 ppm, with no change in hardness per Tetra easystrips test. Flowrate is in the advertised range of 1-2 GPM at tap water pressure."
I thought I'd post it and see what people thought. It lists a capacity of 12,000 mg/L but doesn't say if it's that's for N, NO3 or CaCO3. Another small anion exchange filter I've seen lists the capacity as 3,000 mg/L nitrate (as CaCO3). lol
J
jaws7777
Is your nitrate removal filter similar to this? Yours is probably larger but is it in a filter cartridge or cartridges?