Hi, I'm new here and new to PL. I've been reading through the posts but have not figured out what I should do.

I have three air pumps running at different intensities (low, med, high). They are on S1, S2, and S3.
I need them to operate in sequence S1-S2-S3 for 10 seconds each but with a random time delay start for each pump.

In other words, I need S1 air pump to start between 3600s and 4800s then be on for 10 seconds and then shut off.
Then S2 pump timer starts and the air pump is activated sometime between 3600s and 4800s for 10 seconds,
then S3...

The sequence of S1-S2-S3 would need to run for 24hours then stop.

Sounds weird, maybe but I am recording cephalopods for my research and I'm running air through air stones to see how they react when they are alert/active vs. when they look like they are asleep. It's a way to test whether what they are doing can be defined as sleep. (They should be less responsive when in the sleep-like state.)

I thought I could use switching cycles with three pairs of ON-OFF commands but the limit is 6 cycles so on the short end that may end up with the air stopping after 19 hours instead of 24.

I tried working with the "wave maker" with group settings and had the pumps alternating one after the other using Sequence 1 (or 2). They were each on for 10 seconds one right after the other but I couldn't see how to introduce a window (3600-4800s) delay between pump activation.

This brings me to thinking I may need PL but I am making myself dizzy trying to figure it out. I can't figure out if the sockets should be assigned to a Timer 1-3 or to a GroupPump 1-3, or to a PL.
I want to understand PL so I can program other stuff eventually- it's a really powerful tool! I've seen reference to a PL manual here but the link is a dead end.

1) Could someone post a link to the PL manual and any other guides for GHL PL?
2) If you have a solution to the air pump problem, I'd love to hear it!
3) Please dumb down any explanations as I am a complete novice.
4) Thank you for your time and patience. It is very much appreciated!