[masraum]

Originally Posted by Jolly Amaranto

"Shouldn't there be a cap on the vent on the roof?"
No, what little rain that falls into the opening will not be a problem. Your septic system should handle it.

OK, I was thinking that leaves or insects/animals could cause issues, but it seemed pretty clean/clear from up on the roof looking down.

Sounds like there is a restriction of some sort in the big pipe flowing to the tank. The snake makes it past it but lots of water backs up and only allows a trickle. Remove that big cleanout plug under the house and run a rotating rooter straight through to the tank. You can get these at Lowes or Home Depot. Gona have to get down and dirty in the crawl space.

OK, so the theory is that the 1/4" snake is screwing it's way through but not doing the trick.

I guess what you're saying I need is something like one of these?