[JackieW]

I used to set my Liquid Logic analogue pump controller to between 4 and 5 for first few years.
Over past few months  I've been using it set to about 7.
I'm now having to set it to full 10 to get a workable flow.

Battery not that old.

Could it be the strainer needs replacing/cleaning? If so, has anyone unscrewed the lid?
It looks well set and I'm afraid I'll crack it.

[Plankton]

They tend to build up with crud if you don't clean them out. Grip the main body so you're not putting pressure on the ports when you turn the cap.

[Missing Link]

It comes off easily enough.  I run it under a tap, scraping it with a cotton wool bud (the cotton comes off but the plastic stick still works).

Then screw it back on.  Five minute job.