Pothos work great to remove nitrate from your water but you will need a lot, I meant a loooooot
I used 2 buckets of pothos I bought from Home Depot (10 bucks per bundle) on 40B with light bioload and it's work great. IMO if you have a heavy bio load system them you still need to do WC to keep thing in check but not as often and as much water to change each time.
Edit:
You can start with few pothos and just re-plant the one that grow too long, or let the pothos vine (not leaves) touch the water and it will spout out some roots and create a nature look of roots vine in water.