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My Ludwigia stems are super thin and weak, almost like they're stretching. I've got a 20 gallon tank with a Fluval Plant 3.0 light, running 8 hours a day. Substrate is Fluval Stratum, and I dose Thrive twice a week. Water params are good, 0 ammonia, 0 nitrite, 10 nitrate. Any ideas what's going on?

Thin stems often mean not enough light or nutrients. Your light might not be strong enough for Ludwigia, especially if it's stretching. Try bumping up the intensity or duration. Also, check your potassium levels, as deficiencies can cause weak stems.

The light is insufficient. Ludwigia requires high light intensity. Increase the light duration to 10 hours and ensure the spectrum is correct. Stratum is adequate but may lack trace elements. Test for potassium and iron deficiencies.

I had the same issue with my Rotala. Turned out my light was too weak. Upgraded to a stronger one and the stems thickened up in a few weeks. Maybe try that?

Yo, sounds like your plants are starving for light. Ludwigia's a hungry beast, gonna need more juice from that light. Maybe crank it up or move it closer to the surface. Also, check if your Thrive's got enough potassium, that's key for stems.

RiverKai wrote: ↑Sat Aug 23, 2025 10:23 pm Yo, sounds like your plants are starving for light. Ludwigia's a hungry beast, gonna need more juice from that light. Maybe crank it up or move it closer to the surface. Also, check if your Thrive's got enough potassium, that's key for stems.

Yeah, I agree. Light's prolly the issue. My stems were skinny till I fixed the light. Now they're chonky.

Thin stems can also be from overcrowding. If the plants are too close, they'll stretch for light. Make sure they've got space to grow properly.

It's likely a combination of light and nutrients. Ludwigia needs high light and plenty of potassium. If your light's at max, consider adding a reflector or supplementing with root tabs. Also, check your CO2 levels if you're injecting.

I'd second the light and nutrient advice. Ludwigia's a heavy feeder, so make sure your dosing schedule matches its needs. Also, trim the tops to encourage thicker growth lower down.

hikers_22 wrote: ↑Sun Aug 24, 2025 12:33 am I'd second the light and nutrient advice. Ludwigia's a heavy feeder, so make sure your dosing schedule matches its needs. Also, trim the tops to encourage thicker growth lower down.

Trimming's a solid tip. I've found that cutting back the tops forces the plant to focus on strengthening the lower stems. Works like a charm.