Aquaboy clock frequency

[ggarms]

Hey guys, finished my aquaboy (2x 3008) and The pedal is working and delaying I am just trying to fine tune the clock/delay time. I've removed the whine from the signal when not playing, but I do notice a slight hint of it on my repeats. I noticed that the lowest I am able get the clock freq to is around 8hz. Any thoughts on where to start? I measured my delay pot at 1.002m.