I fought this for weeks and kept blaming air leaks too, but my hose was fine the whole time. What finally clicked was realizing the suction wasn’t dropping all at once, it was fading as I went. By the time I hit the deep end, the system was already choking a bit.
In my case the pump basket wasn’t totally packed, but it was loading up with really fine junk as I vacuumed. Stuff you don’t notice right away. Filter pressure would only creep up 1 or 2 psi, nothing dramatic, but it was enough to kill flow at the vacuum head. When I shut the pump off and restarted it, everything resettled and felt “fixed,” which is why it was so confusing. It wasn’t fixed, just temporarily relieved.
What helped was doing a proper filter clean instead of just rinsing and calling it good. I soaked the cartridges with aquadoc pool filter cleaner and a ton of fine gunk came out that I didn’t even know was there. After that, suction stayed steady all the way through vacuuming and I didn’t have to keep stopping. Now I also empty the pump basket once mid-clean if the pool’s dirty. Bit of a pain, but way better than restarting the system every 10 minutes. Anyone else notice fine debris causes more trouble than leaves ever do?