Accidentally bought a fistful of Riccia fluitans because “floating green hairdo” sounded cute, and now I’m considering weaponizing it across my plant shelves. Plan: turn all my pebble trays and semi-hydro reservoirs into shallow wetlands so the Riccia can mop up nutrients, crank humidity for the drama queens, and maybe moonlight as a gnat-proof lid. Before I scale this from “quirky science” to “OSHA violation,” can anyone sanity-check the following?
- Survival in still trays: Will Riccia tolerate 1-2 cm deep, stagnant water under plant shelves, or does it demand pond-level water movement to avoid turning into Eau de Swamp?
- Emersed-ish life: In open air rooms (45-60% RH), can Riccia stay happy as a floating mat with occasional misting, or does it basically melt unless humidity is terrarium-grade?
- Light and schedule: Is 8-10 hours at 100-200 PPFD under 6500K shop lights enough, or am I about to cultivate premium string algae instead of Riccia?
- Fertilizer runoff: Semi-hydro nutrient soup ranges 300-800 µS/cm. Is that a Riccia buffet or a Riccia funeral? Any GH/KH ranges it absolutely hates?
- Gnat barrier: If I cap semi-hydro pots or trays with a tight Riccia mat, does it actually slow fungus gnat access, or do they just treat it like a VIP velvet rope?
- Smell control: Tips to keep the “wet biofilm funk” from developing? Weekly turkey-baster water swaps? A pinch of crushed coral? Leaf litter? Ritual chanting?
- Anchoring without going feral: Best way to keep it where I put it-plastic canvas raft, hairnet over LECA, embroidery mesh rings-without turning maintenance into a weekly haircut montage?
- Cross-contamination risks: Anyone had riccia introduce hitchhikers (scuds/planaria/hydra) into houseplant setups, or is that mainly an aquarium problem?
- Winter mode: Does it sulk when room temps drop to 18-20°C and the air gets drier, or is it the stoic green carpet of my dreams?
- Pet curiosity: If a cat samples the “floating salad bar,” am I calling a vet or just filing a complaint with management (the cat)?
- Harvest math: Rough growth rates without injected CO2? If I start with a ping-pong ball, am I pruning weekly, or will I die of old age first?
- Humidity ROI: Anyone measured actual RH changes from covering pebble trays with Riccia vs. bare water? Is the humidity boost real or placebo with chlorophyll?
Bonus chaos idea: Using Riccia as a living top-dress on LECA to block algae and splash. Keep the top layer damp with wicks and occasional misting. Does it adapt, or does it crisp up into artisanal liverwort jerky?
If you’ve tried “houseplant bog lite” with Riccia, I’d love your settings: light, water depth, TDS/GH/KH, change frequency, and how you kept the vibe “spa” instead of “swamp.” Also open to “please stop” stories if this ends in a biblical-scale bloom of mystery critters.