I have recently been getting a few requests for how to adjust dosing with all of my research on the hanna checker and copper power being used together. Figured I would throw this up as a point of reference. For anyone using Copper Power: Bottle concentration will bring you to a Cu level of 2.5ppm if dosed as instructed. Although it is not always necessary to dose your QT with a level that high. Copper power is considered therapeutic at a Cu Level of 1.5ppm. 1.5ppm is the MINIMUM. I personally have been using Copper Power at a level of 1.75ppm using the hanna checker to make sure I maintain a level safely above the Minimum. You can see @Humblefish's communication with Endich, the manufacturer of Copper Power in the thread below, verifying the minimum level of 1.5ppm https://www.reef2reef.com/threads/chelated-copper-is-chelated-copper.373513/ To figure out how to adjust the dosages follow these easy steps; Total gallons x 1.475ml = Total ml to reach 2.5ppm Now Take 2.5ppm / Total ml = PPM per ML Dosed Now take desired target / PPM per ML Dosed = Total ml needed to reach desired target For Example my QT is a 40b. Subtract displacement Add HOB filter volume. I have exactly 40 gallons of water to treat. 40gal x 1.475ml=59ml 2.5ppm / 59ml= .042ppm per ml dosed 1.75ppm / .042ppm = 41.7ml Total I called it 42ml total. Ramped up over 7 days (6ml per day split into 2 doses, 3ml in am/3ml in pm) You can then take the total ml needed for your volume and split it into whatever dosing schedule or "ramp up" you desire. Edit: I should have mentioned in my original post if you are using the Hanna checker to test you can do so after each dose, or every other dose and figure out exactly how many ppm you should be increasing using the above ^^^ equation. This will also indicate if you are encountering any absorption. Here are also some simple guidelines if you don't want to do the math above or are using visual test methods. This is a little less accurate than above (Just trying to keep from going out 10 decimal points), but will get you darn close. 1.48ml per gallon = 2.5ppm 1.33ml per gallon = 2.25ppm 1.18ml per gallon = 2.0ppm 1.04ml per gallon = 1.75ppm .89ml per gallon = 1.5ppm No matter which formula you use above, make sure to take the following into consideration. *This only works if you aren't encountering any absorption. *You also need to measure the volume of water in QT, for example don't just assume a 20 gallon tank to hold exactly 20 gallons (You have to consider displacement and what level you are filling the tank to, also volume of HOB if you use one.). *MAKE SURE TO TEST FREQUENTLY *If you see signs of velvet it is not recommended to use the 5-7 day ramp up period, you would want to reach at least 1.5ppm within 48 hours. API, Hach, Chemetrics, and Hanna are all suitable test methods for copper power.