No problem. As the meds do their job then the effective medicine in the tank will dilute, so thats why you will need to dose every 24 hours. I'm actually not sure if its solely the meds that actually kills the bacteria itself that gets consumed in the process, or if adding it to the tank causes the meds to break down as well, but if you only dose once, it wont kills all the bacteria and some if not all forms of bacteria will become resistant to meds. Thats why its incredibly important to follow the directions of all meds to the T and to continue to dose untill all the bacterias gone, which is usually well after the physical symptoms have healed.