I have the Phosphate LR checker that I bought 10-15 years ago. I am just getting back into the hobby and wondering if I should buy the Phosphate ULR or the Phosphorus ULR checker? I plan on keeping an sps dominated tank, but probably will not ad coral for close to a year. I know the lr has a +/-.04, and from what I have seen it is best to keep phosphate at range of about .05-.15 ppm. If I am to keep it around .1 I should stay in that range. I guess my concern is it will be hard to keep a tank rock hard at .1, so if it get a reading of .05, the tank could be as low as .01 or up to .15 the tank could be as high as .19. Would this range be too much?