I am qt butterfly angle and scopas tang in a 20 gallon long tank . I am dosing prazipro and today will be day 3 of the treatment. I tested my water and i have a ammonia spike of 2ppm. My question is i am going to do a 50 percent water change, what do i do about the prazipro levels. Do i re dose? I am kind of stuck on what to do.