Hygrophila lancea 'Araguaia' (Araguaia hygro) care

Light

Hygrophila lancea 'Araguaia' is what florists mean by "bright spot, no direct sun" — close enough to a south or east window to feel the brightness, with a sheer curtain or a few feet of distance keeping the sun off the leaves. Submerged plant needing high-intensity aquarium LED of roughly 50-80+ PAR at substrate level. Strong light plus CO2 brings out the red-purple flush; under low light it reverts to plain green and grows leggy. A phone lux-meter at the leaf surface should read 1,500-3,000 lux at noon.

Watering

Water hygrophila lancea 'araguaia' submerged permanently; 25-50% aquarium water changes weekly. The actual day count varies with pot size, light, and season — the finger test (or lifting the pot to feel its weight) is more reliable than a fixed calendar. Empty any drainage saucer afterwards so the pot isn't sitting in water. Grows underwater in a freshwater tank. Keep soft to moderately hard water (2-12 dGH), pH 6.0-7.5. Pressurised CO2 (20-30 ppm) is effectively required for compact growth and good colour.

Soil and pot

Hygrophila lancea 'Araguaia' grows best in nutrient-rich aquarium aquasoil substrate. Root in an active aquasoil (e.g. ADA Amazonia type) or fine gravel capped over nutrient base. It is a heavy root feeder, so a fertile substrate plus root tabs supports the best growth. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Hygrophila lancea 'Araguaia' sits happiest at around 100% (submerged aquatic) humidity and 22-28°C (72-82°F). Cultivated fully underwater, so ambient humidity is not relevant. Emersed (out-of-water) growth is possible in a humid paludarium above 80% but the leaf form and colour differ from the submerged plant. If you keep the room above 22 year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed hygrophila lancea 'araguaia' sparingly. Dose a full liquid macro and micro fertiliser regimen in the water column (nitrate, phosphate, potassium plus trace/iron) plus root tabs in the substrate. Lean dosing with consistent iron supports the strongest red coloration. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on hygrophila lancea 'araguaia' in the Growli community. Each is annotated with the most common cause so you know where to start.

• Loss of red colour / reverting to green — Insufficient light or low CO2 makes new growth plain green and stretched. Raise PAR, confirm CO2 reaches 20-30 ppm, and keep iron dosing steady.
• Stunted or twisted tips — Usually a micronutrient deficiency or fluctuating CO2. Stabilise CO2 across the photoperiod and ensure adequate magnesium, calcium and trace elements.
• Lower-leaf melt after planting — Emersed-grown nursery stems often shed leaves when transitioning to submerged form. Keep parameters stable and trim, and new submerged growth will follow.
• Algae on slow new growth — Its slower pace lets spot and hair algae colonise leaves in unstable tanks. Improve flow, balance light to CO2, and keep nutrients consistent.

Propagation

Cut healthy side shoots or top 5-8 cm of a stem and replant the cutting in the substrate; the trimmed parent stem branches at the cut. Standard stem-plant trim-and-replant propagation. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Hygrophila lancea 'Araguaia' is mildly toxic to pets. Hygrophila is not individually listed by the ASPCA on either the toxic or non-toxic plant lists, so its pet status is unconfirmed. Treat with caution and verify with a vet; as a submerged aquarium plant, casual ingestion by cats or dogs is unlikely. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Hygrophila lancea 'Araguaia' deep-dive guides

Every aspect of hygrophila lancea 'araguaia' care, each with its own calibrated guide:

• Hygrophila lancea 'Araguaia' watering schedule
• Hygrophila lancea 'Araguaia' light requirements
• Best soil mix for hygrophila lancea 'araguaia'
• Hygrophila lancea 'Araguaia' fertilizing guide
• When to repot hygrophila lancea 'araguaia'
• How to propagate hygrophila lancea 'araguaia'
• Hygrophila lancea 'Araguaia' growth rate & size
• Hygrophila lancea 'Araguaia' cold hardiness
• Hygrophila lancea 'Araguaia' temperature & humidity
• Is hygrophila lancea 'araguaia' toxic to cats & dogs?
• Is hygrophila lancea 'araguaia' toxic to cats?
• Is hygrophila lancea 'araguaia' toxic to dogs?

Featured in these plant shortlists

Hygrophila lancea 'Araguaia' qualifies for 2 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best plants for a north-facing window — Houseplants for a north-facing window: bright, even, indirect light and no scorching direct sun. Each pick verified against its documented light needs.
• Best small & tabletop houseplants — Compact houseplants that stay under about 40 cm — desk, shelf and windowsill plants that never outgrow a small space.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

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Hygrophila lancea 'Araguaia' is also commonly called Araguaia hygro or lance hygrophila.

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