Care specifications
| Type | Moss |
|---|---|
| Difficulty | Medium |
| Light | Medium (35–70 µmol PAR) |
| CO2 | Beneficial, not required |
| Fertilizer demand | Medium |
| Growth rate | Fast |
| Max height | 2 in |
| Spread | 6 in |
| Placement | Floating, Foreground |
| Attaches to hardscape | No |
| Snail & shrimp safe | Yes |
| Temperature | 65–82 °F |
| pH | 6–7.5 |
| Color | Green |
| Trimming | Frequent |
| Styles | Iwagumi, Nature |
Get Riccia
Propagation
Divide the thallus by hand — every fragment keeps growing, floating or re-tied to stone.
Frequently asked questions
Why does my Riccia keep floating away even though I tied it down?
Two culprits: untrimmed growth shades the lower layer until it dies and lets go, and oxygen bubbles from heavy pearling build up under the mat and lift it. Trim weekly, press the mat gently to release trapped gas, and refresh the mesh or thread every month or two — Riccia has no roots and never attaches on its own.
Can Riccia carpet without CO2?
Realistically no — without injected CO2 it grows loose and stringy and detaches rather than forming the dense anchored cushion. It is still an excellent low-tech plant, just as a floater, where it gets all the CO2 it needs from the air and provides great fry and shrimp cover.
Riccia appears in
Find plants for your tank
Four questions — size, light, CO2, goals — and a ranked list matched to your exact setup.
Open the plant finder →