Might be able to help with the first part.
I have a clip on fan in my canopy that I have on for 4 minutes, and off for 3, and then off when the lights are off.
Fallback ON
OSC 000:00/004:00/003:00 Then ON
If Time 23:10 to 11:00 Then OFF
So, if you changed the "004:000" to "052:000" and the "003:000" to "008:000", that should (( key word "should" )) cover the first part.
For the second part, I believe that "If Time 05:01 to 23:59 Then OFF" Would turn it off from 5:01 AM to 11:59 PM, which seem to be what you want.
For the 3rd part, and this is 100% a guess. I would think that something like "If ph < (( or is it > )) 8.4 Then OFF" Might need to name the pH probe, but not sure.