My tap water has nitrates of about 30ppm. I am basing my dosing around James' PMDD page (http://theplantedtank.co.uk/PMDD.htm, thanks for the awesome site!). Presumably if my plants use approximately all the nitrate added each day then I should add just as much nitrate as anyone else. In this scenario my nitrate level will just stay around 30ppm. Is this fair? James' guide mentions that with high starting nitrates you may be able to dose less. Just wonder what people's experiences have been? Thanks.