I would leave all the filter pads as they are. Leave them alone. You'll need to do water changes in order to get that free swimming bacteria in place. What you are trying to do is have your beneficial bacteria to establish and with the constant or seemingly constant rinsing of them, you keep disrupting the system by putting the pads under the tap, killing what is there and forcing what is in the tank to build more and more. With the new filter in place, it shouldn't need to be cleaned until way after your established. Let it run and do its thing. You'll get there, just be patient