Overview
Vallisneria is a fast-growing grass-like background plant whose ribbon leaves rise straight to the water surface and then trail along it, creating a flowing jungle backdrop.
It spreads quickly by runners, quickly carpeting the back of a tank, and tolerates a wide temperature range including unheated coldwater tanks.
| Difficulty | Easy |
| Light | Medium |
| CO2 | Not required |
| Growth rate | Fast |
| Placement | Background |
| Max height | To the surface (18 in+) |
| Feeding | Root feeder |
| Temperature | 64-82°F (18-28°C) |
| Propagation | Runners |
Light & CO2
Medium light drives good growth; CO2 is optional and speeds spreading. Under strong light it grows fast enough to need regular thinning.
Planting & placement
Plant individual crowns in the substrate at the back, keeping the crown just above the surface. Its tall leaves will reach and lay across the surface, so give it the background and expect it to shade what's behind it.
Feeding & growth
A root feeder that benefits from root tabs in inert substrates. It grows fast and spreads by sending out runners with new plantlets , thin these regularly or it takes over.
Propagation
Simply let the runners produce daughter plants; once they have roots you can separate and replant them, or leave them to form a dense stand.
Common problems
Melting after planting is common as it adapts; new growth from the centre is the sign it has settled. It is sensitive to liquid carbon (glutaraldehyde) products, which can melt it.
Fun facts
- Vallisneria spreads by runners and can carpet a background in weeks.
- Its leaves grow to the surface and then trail along it, forming a canopy.
- It tolerates cool water, so it works in unheated coldwater and goldfish tanks (with care).
- It is sensitive to liquid-carbon (glut) products, which can melt it.
- A true root feeder , root tabs help it thrive in inert gravel.
Frequently asked questions
How fast does Vallisneria grow?
Fast. Under medium light it spreads quickly by runners and its leaves reach the surface, so it usually needs regular thinning.
Does Vallisneria need CO2?
No. It grows well without CO2 under medium light; CO2 simply accelerates its already fast spreading.
Why did my Vallisneria melt after planting?
Melting is a normal adjustment to a new tank or to being moved. As long as the crown is healthy, new leaves will grow from the centre. Avoid liquid-carbon products, which can melt val.
How do you plant Vallisneria?
Plant each crown in the substrate at the back of the tank with the crown (where leaves meet roots) just above the surface, and add root tabs in inert gravel.
Can Vallisneria grow in cold water?
Yes, it tolerates cooler temperatures and is often used in unheated coldwater and goldfish tanks, though goldfish may uproot it.
