Rainwater toilets and greywater showers: City tries new water-saving tricks

Ever tried one of those wet/dry shop vacs to suck out the sludge? Wondering if that’d make things less gross or just move the mess around...

Tried the shop vac route once on a greywater holding tank - honestly, it worked but only up to a point. You’ll pull out the loose stuff, but the heavier gunk tends to cling to the bottom and corners. Ended up having to go in with a brush anyway. If you do use a vac, make sure you’ve got a filter that can handle wet debris, otherwise you’ll just end up clogging it and making more work for yourself. The mess factor doesn’t really go away, it just changes form...

I’ve gone the shop vac route too, and yeah, you’re right - the initial “wow, look at all that stuff coming out” moment doesn’t last long before you hit the stubborn layer. The first time I tried it, I thought I’d be clever and line the tank with a plastic sheet beforehand to make cleaning easier, but the sheet just bunched up and made it worse. Ended up with a messier job and a lot of cursing.

If you’re trying to keep costs down and avoid specialty tools, I’ve found a cheap paint scraper does a decent job dislodging the stuck-on sludge before you vacuum. It’s not glamorous, but it works. Just be careful with plastic tanks - some of them scratch up pretty easily, and that can make cleaning harder next time.

As for the filters, totally agree - don’t skimp there. I learned the hard way that not all shop vac filters are created equal. The standard ones clog up fast with wet gunk, and then you’re left cleaning the vac itself, which is arguably worse than just dealing with the tank sludge.

One thing I did pick up is to let the tank dry out a bit before cleaning. If you can time it so there’s not much water left, the sludge is less soupy and easier to scrape out. Still gross, but at least you’re not dealing with a sludge smoothie.

Honestly, no matter what method you pick, it’s a hands-on job. The vac helps, but there’s always some elbow grease involved. I guess that’s just part of the deal with these water-saving setups… they’re great for the utility bill, but maintenance is a whole other story.

I get what you’re saying about the elbow grease, but I’m not totally convinced it has to be such a pain every time. I’ve actually started using a long-handled toilet brush (the cheap kind, nothing fancy) for the first pass at the sludge, and it’s way less hassle than scraping. It doesn’t scratch up the plastic either, which was a problem for me with metal scrapers. Maybe it doesn’t get every last bit, but it loosens enough that the vac can handle most of it.

Also, I’ve been wondering if there’s a way to cut down on the buildup in the first place. Like, would adding a mesh pre-filter or even just rinsing out the tank more often make a difference? Sometimes I feel like we’re all just resigned to the gross factor, but maybe there’s a smarter workaround.

And yeah, filters are a whole saga. I tried those “universal” ones once - never again. The clogging was unreal. If anyone’s found a reusable filter that actually works, I’d love to hear about it...

Mesh pre-filter’s a solid idea - just make sure it’s fine enough to catch the gunk but not so tight it clogs up every week. I’ve seen folks use nylon stockings as a DIY pre-filter, actually works better than half the “universal” ones out there. Rinsing more often definitely helps, but honestly, some buildup’s just part of the deal with these setups. If you ever find a reusable filter that doesn’t turn into a science experiment after a month, let me know... I’m still looking too.

Honestly, I’ve tried the nylon stocking trick too, and you’re right - it’s surprisingly effective for something so basic. But man, keeping up with rinsing those things gets old fast. I’ve seen some folks swear by stainless mesh screens, but even those seem to get slimy after a while if you’re not on top of maintenance.

Here’s the thing: I’m not convinced there’s a “set it and forget it” filter for these rainwater setups, at least not at a reasonable price point. Maybe it’s just the nature of dealing with all that organic debris? I’ve wondered if adding a first-flush diverter would cut down on the gunk before it even hits the filter - anyone tried that? Or is it just another thing to clean?

Seems like every solution just shifts the hassle somewhere else...