im trying to add copper medication to my quarantine tank that is a 5 gallon.my medication states-use at 2.5 ppm-one fluid ounce to each 20 gallons,i have nothing that measures anything in liquid ounces,i just have something that measures liquid in milliliters,so how many milliliters of this medication do i add to my 5 gallon qt tank to obtain a 2.5 ppm reading.any help will be greatly appreciated.thanks.