I asked this question before and looked online and for nitrosorb stuff but that didn't seem like it would help much. I have well water and my water comes out of tap at 40ppm. I keep up with everything but if it comes out that high i can't get it lower. Is their something i can buy to remove the nitrates from the tap?? My fish seem fine but i know they would do alot better in 10ppm nitrates.