I've been using a gravel filter setup for my greywater system for about three years now, and debris hasn't been a huge issue. Every few months I do have to rake off the top layer of leaves and gunk, but it's pretty straightforward—takes maybe 15 minutes tops. One thing I'd suggest is putting some coarse mesh or screen above the gravel bed; it catches most of the bigger stuff and makes cleanup way easier. Have you thought about how deep you'll make your gravel layer?
I've seen setups with mesh screens, and yeah, they do help a lot with the bigger debris. A buddy of mine went a bit overboard though—used a really fine mesh thinking he'd catch absolutely everything. Ended up clogging constantly, and he spent more time cleaning the screen than anything else, lol. Finding that sweet spot between too coarse and too fine is key. Curious if anyone's tried layering different gravel sizes to improve filtration? Seems like it might help...
"Curious if anyone's tried layering different gravel sizes to improve filtration? Seems like it might help..."
Tried exactly that on a rental property a couple years back—layered coarse gravel at the bottom, medium in the middle, and fine stuff up top. Worked pretty well initially, but eventually the finer gravel got compacted and slowed drainage way down. Ended up tweaking it by swapping out the top layer for something slightly coarser, and it's been smooth sailing since. Might be worth experimenting with different combos to find your own sweet spot...
Did something similar for my greywater setup, but honestly, I found sand layers mixed with gravel worked better than gravel alone. Gravel-only setups clogged faster in my experience...sand seems to catch smaller particles without compacting too badly. Might be worth a shot.
"sand seems to catch smaller particles without compacting too badly. Might be worth a shot."
Yeah, sand definitely helps with finer particles, but from my experience, it can still compact over time if not maintained properly. I've seen setups where sand layers were great initially, but after a while, they started slowing down drainage significantly. Gravel alone does clog quicker, you're right about that...but sometimes the sand layer can become its own headache if you don't keep an eye on it.
Still, your approach sounds practical and well thought-out. Regular maintenance and occasional stirring or replacing of the top sand layer usually keeps things running smoothly. Good on you for experimenting—greywater setups are always a bit trial-and-error anyway.
