What is your water volume?Ok now I'm confused. I saw earlier that you should shoot for a dwell time of an hour or sow. If that's the case 1 GPH is equal to 63 ml/min. 10% of my volume per hour would be 17 ml/min so much slower. If the concentration of nitrates is fixed at let's say 100ppm does it really matter what the volume is? 10 gallons at 100ppm is the same concentration as 100 gallons at 100ppm wouldn't it just bring them down faster in the smaller volume?