S Sarah88 Fire Eel MFK Member Sep 27, 2009 3,919 7 68 Wilmington, NC Jul 9, 2010 #11 yeah i always just hold the tube up against the white part of the card and look at it right up against the color scale, but like others have said, if its in the red either way you should do a water change to try and keep it below 20
yeah i always just hold the tube up against the white part of the card and look at it right up against the color scale, but like others have said, if its in the red either way you should do a water change to try and keep it below 20