great question...............there have been several threads on fast flow towers reducing nitrATE levels.... although no one can say why or how this would have any affect on nitrate levels.........i have never gotten my nitrates below 20 ppm with what i see as massive 24/7 water changes ( 1000 gallons/day) with no nitrates in the make up water......
so :
1) more bio filtration is good ( think tank expansion as sam the gigas grows)
2) i will be monitoring the nitrate levels in the tank to see if there is any measureable change
do you think any common tests could show a change in one pass.....its about 50 gpm.....not much contact time.
thanks for looking......you input is always appreciated