A small world,
Your Opae ‘Ula shrimp ecosphere is one of the lowest-maintenance pets you'll ever keep — but a little understanding goes a long way. Here's everything you need to know to help your tiny world thrive for years.
Meet your shrimp.
Inside your ecosphere live ‘ōpae‘ula — Halocaridina rubra — tiny brackish-water shrimp endemic to the volcanic anchialine pools of Hawai‘i. They are small, brilliantly red, and remarkable.
In the wild, ‘ōpae‘ula live in geothermally warm pools tucked inside lava rock, fed by a hidden mix of seawater seeping up and freshwater seeping down. Conditions there shift constantly — and these shrimp have evolved to handle it. They tolerate a wider range of salinity, temperature, and pH than almost any other aquarium animal you can buy.
That hardiness is what makes a sealed or semi-sealed ecosphere possible. Algae produce oxygen and food. Bacteria break down waste. The shrimp graze. The cycle continues, quietly, for years.
Ideal conditions.
Your ecosphere arrives perfectly balanced. These are the parameters it's been built around — useful to know, but you don't need to test or adjust anything.
Light & placement.
Light is your ecosphere's only real food source — it's what lets the algae photosynthesize, which feeds the shrimp and produces oxygen. But the right amount matters more than you might think.
Bright, indirect light is the goal. Direct sunlight will cook a sealed ecosphere in hours.
A shelf, desk, or windowsill that gets ambient daylight — but where the sphere itself never sits in a beam of sun — is ideal. North-facing windows are usually safe. South or west-facing should be avoided unless the sphere is several feet back from the glass.
If natural light is limited, a small LED desk lamp on a 6 – 8 hour daily cycle works beautifully. The shrimp also need a dark period, so don't leave a light on around the clock.
Feeding — or not.
In a balanced ecosphere, you should not need to feed your shrimp. They'll graze on the biofilm and algae that grow inside the sphere, and their metabolisms are slow enough that they can go weeks or months without supplemental food.
If you have an open or semi-closed system and want to offer something occasionally, a single grain of spirulina or a tiny crumb of an algae wafer once every 3 – 4 weeks is plenty. Less is always better.
The single most common way people kill their ‘ōpae‘ula is by feeding them too much.
Uneaten food fouls the water, spikes ammonia, and can collapse the entire ecosystem in days. When in doubt, don't feed.
Topping off water.
Sealed ecospheres need almost nothing from you. Open or semi-closed setups will lose a little water to evaporation over time — and when they do, this is the only maintenance you'll do.
Top off with distilled water only. Never tap water, never bottled spring water, and never more saltwater. Evaporation only removes water — the salt stays behind. Adding more saltwater would slowly raise the salinity past what your shrimp can tolerate.
Pour slowly down the side of the glass to avoid stressing the shrimp. A turkey baster or small dropper is perfect.
Do's & don'ts.
Do
- ✓ Place in indirect, ambient light
- ✓ Keep at room temperature 68 – 80°F
- ✓ Top off with distilled water as needed
- ✓ Watch and enjoy — daily observation is healthy
- ✓ Trust the cycle. Less is more.
Don't
- × Place in direct sunlight
- × Place near heaters, vents, or A/C
- × Add tap water, ever
- × Overfeed or feed at all, in most cases
- × Shake, tap, or move the sphere unnecessarily
When something looks off.
‘Ōpae‘ula are dramatic creatures. Some changes look alarming but are entirely normal. Here's how to read what you're seeing.
Usually, no. Opae ula can look pale after molting, when resting, or when the lighting changes. Give them time and avoid sudden changes to the ecosphere.
It may be a molt, not a dead shrimp. Molts look like tiny clear shells and are normal. Leave it inside because the ecosystem will break it down naturally.
Cloudy or green water usually means there is too much light or extra nutrients. Move the sphere away from direct light and avoid feeding.
They may be hiding in the substrate, behind algae, or resting in a shaded area. Check again at different times of day before making any changes.
Small floating particles can be biofilm, algae, or harmless microorganisms. In most balanced ecospheres, this is normal and does not require action.
No major changes are needed. Keep the sphere in stable indirect light, top off only if needed, and let the ecosystem continue its cycle.
We’re here to help your tiny world thrive.
Every Shrimp Ecosphere comes with our care guarantee. If you ever have a question — about light, water, lifespan, or what you're seeing inside the glass — reach out and we'll help.