Can Cylindric Ludwigia and Guppy Grass Grow Together?

Cylindric Ludwigia and Guppy Grass share a workable water window around 20 to 28 °C, pH 6 to 7.5, and 2 to 12 dGH.

Both plants are comfortable in freshwater, so salinity is not a meaningful obstacle.

Flow is workable if the layout gives Cylindric Ludwigia moderate flow and Guppy Grass gentle, low-flow water.

The care split shows up in light or CO2. Cylindric Ludwigia wants high light and recommended added CO2, while Guppy Grass wants low light and no added CO2.

Both plants naturally lean toward the midground and background, which is why spacing, pruning, and final mature size matter more than they do in a more staggered planting mix.

Cylindric Ludwigia reaches about 40 cm tall by 12 cm wide, while Guppy Grass reaches about 60 cm tall by 15 cm wide. Use those mature sizes for the layout, not the small nursery portions you bring home.

Shade is worth watching, but it is usually manageable through trimming and a little spatial separation.

Cylindric Ludwigia is typically rooted in substrate with nutrient-rich substrate preferred and feeds mainly as a mixed feeder. Guppy Grass is typically rooted in substrate with inert substrate is fine and feeds mainly as a water column feeder. That difference can make the pairing easier to arrange than two plants fighting for the exact same root or attachment zone.

They can share the space, but the scape will stay cleaner if you leave more room than the labels alone might suggest.

Cylindric Ludwigia brings moderate growth, moderate maintenance, and advanced difficulty. Guppy Grass brings fast growth, moderate maintenance, and beginner difficulty. If one grows much faster, trim that plant before it starts making the other look like the problem.

The practical watch-outs are that one plant is much more light-hungry, so the scape will need placement and trimming discipline; and that their nutrient appetites are far enough apart that dosing will need a closer eye; and that both plants tend to work in the midground and background, so spacing matters more than usual; and that you will want to leave more room than usual for mature spread and routine thinning; and that the layout needs a little thought so one plant does not slowly dim the other; and that growth pace and maintenance rhythm are uneven, so the stronger grower can dominate if pruning slips.

The strongest reasons to try the mix are that they share a workable temperature window around 20 to 28 °C; and that their flow preferences sit close enough to tune one layout around both plants.

Skip this pairing for most display tanks unless you have a specific reason to experiment. A better long-term choice is a partner plant that shares the same water window and asks for less compromise in light, flow, or maintenance.

The simple success test is whether both plants still look healthy after the faster grower has been trimmed several times. If one keeps declining after routine care, the layout is probably asking too much of it.

Cylindric Ludwigia and Guppy Grass are usually better used in separate scapes built around different goals. The practical problem is not that one of them is a bad plant; it is that their long-term maintenance rhythm, spacing, or environmental preferences pull the layout in different directions.