anyone tried rainwater harvesting vs greywater systems for backyard plumbing?

The maintenance difference seems like the part that could make or break the choice. Since you mentioned greywater needs filtering, what routine cleaning and common failure points should a beginner expect with each option, especially clogged filters, pump problems, and algae or sediment buildup in the storage tank?

The maintenance difference can be significant. For greywater, the regular jobs are usually cleaning lint or hair filters, checking that diversion valves and distribution lines are not clogged, and making sure the system is not holding water long enough to create odors. Pumps, if the setup uses one, add another failure point.

Rainwater systems are generally simpler, but they still need gutter and inlet screens cleared, sediment cleaned from filters or the tank bottom, and the tank checked for algae, debris, and mosquito entry. A pump and its intake can also clog, especially if the tank collects a lot of roof debris.

For a beginner, a gravity-fed rainwater setup is often the lower-maintenance option. Greywater can make sense if you have steady laundry or shower water available, but it needs more consistent attention. Is the priority year-round irrigation, or reducing potable-water use during the rainy season?

The gravity-fed rainwater option sounds lower-maintenance, but I’d check the local rules before choosing based on hardware alone. Some areas allow untreated rainwater for drip irrigation but restrict overhead sprinklers, while greywater may require approved plumbing, subsurface distribution, or limits on which fixtures can supply it. Laundry greywater can also be treated differently from shower water.

That could change the practical comparison quite a bit. A simple rain barrel might be fine for hand-watering, but a larger tank connected to irrigation may have backflow-prevention and mosquito-control requirements. Likewise, an untreated greywater system may only be legal for mulch basins or specific landscape plants, not general yard irrigation. The intended method, not just the available water volume, seems like an important first check.

I’d put more weight on when the water is needed than on which setup is simplest. For year-round watering, steady household greywater could be more useful than rain capture, if the local rules and added upkeep work for the intended use. If the goal is mainly to cut potable-water use during the rainy season, rainwater seems the more straightforward fit.

A cautious way to test the fit might be to start with modest rainwater collection for seasonal watering, then see whether dry-season needs still make greywater’s extra upkeep worthwhile. That keeps the first step simple without ruling out greywater if timing turns out to matter more.

What would count as a sign that the rainwater trial isn’t enough - say, regularly running short during the dry season - before taking on greywater’s extra upkeep?

I’d count it as insufficient if the collected water repeatedly runs out during the dry season despite being used for the intended priority, rather than judging from one unusually dry spell. Then compare that recurring shortfall with what greywater could actually supply and whether its use is allowed locally. If it would cover a meaningful part of the gap, the extra upkeep may be justified; if not, it may not solve the problem.

To make that comparison less dependent on memory, someone trying rainwater could jot down when the tank runs dry and whether the priority watering had to be skipped over a typical dry stretch. A recurring gap is more useful to weigh against greywater than one isolated shortage.