How often must I update my reagents? Mine are exactly one year old. I have the tfp-100. Also, when doing the FC test, I put a second vial with clear pool water in it to compare with the vial I'm testing. The question is, should the testing vial be brought to be as clear as the plain pool water? Being color blind, I am trying this method to determine if all the pink is gone. But it seems to me that it never gets as clear as the plain water vial.