Likewise if you can not see the yellow stripe on the card then it is time to change your carbon. Yellowing of the aquarium water occurs over time. The use of activated carbon filters out many things including this yellowing. This simple test shows the effectiveness of the activated carbon. AquaSite or Aquatic Etc, Inc. does not guarantee anything.
All information is a compilation of our experience and success.
We recommend testing of water quality. By your building any DIY projects, you agree to hold AquaSite and Aquatic Etc, Inc. harmless for any damages that may occur. Inc. All rights reserved.