I added the acid at about 6:15 and it is now 8:22 no movement so I guess I will wait till tomorrow . I want to put shock in there but waiting for the PH to come down so it will work better . I will try again at about 9:30 and it nothing changes I will try tomorrow . I can't leave my filter running alll night because it worries my hubby because of the algea floating and he is concerned abou tpressure buiding in the filter