Thanks for the suggestion.

Yes, the mesquite leaves go right through those plastic basket holes. And on the advice of a local pool guy, I have already tried the "ladies hose" version of the sock. For one thing, it seemed quite restrictive even when clean. But then the thing would plug up almost completely over night, requiring cleaning twice a day in the peak leaf season.

I think the main problem is that is just does not have enough surface area. So what I'm hoping to come up with is something like the large/long Hayward in line mesh sock. The hose inlet channels incoming water right down the middle. When it's clean, anything going in goes right to the toe of the sock. As it fills up, it fills from toe to inlet over some 16"-18" or so of mesh "sock". And even half full, there is more open surface area than there is with a clean skimmer sock as shown, plus holes are small enough to block 99% of the mesquite leaves, while still being far bigger than the sock, so flow remains good until it's about 80% full. That cycle usually takes at least 3 or 4 days as long as I keep the piles from collecting around the pool, and we don't have a big wind storm. It's basically perfect for my needs, but only works for the vacuum.

Given that the in-line vac filter/socks seem pretty common, I really thought for sure such a thing would already exist for the main line. Something finer than the plastic baskets (which only catch sticks and Oak leaves) to keep other debris out of the main particulate filter. It seems those filters are really only supposed to catch dirt and relatively small stuff. It (the main filter) sure doesn't seem to handle my problem well, and I can only imagine a DE or cartridge filter would have even more problems with it.

So if there is no commercial product at a decent price, I may try to make something. It has to be serviceable from within a hard line system (near the main filter), so the straight through doesn't really work well (no good way to unscrew and/or pull off the end). If I could find a good source for the mesh sock material, and a suitable sized tank/receiver, I was thinking about something like a "cyclone" style separator system like used for dust collectors (I have a hobby machine shop and decent equipped wood shop). But making it big enough for the water velocity to slow enough to allow any drop-out would be a problem, as would cleaning the main tank and getting at the Hayward style sock inside. May have to visit some local surplus and scrapper yards to see if I can get a serviceable modest sized commercial stainless pressure container with cam lock lid to service as the main tank. Probably have to settle for some sort of mechanical filter using a long mesh sock, depending on what donor parts I can find.