How to quarantine new shrimp (and whether you need to)
New shrimp are exciting, and the temptation is to drip them straight into the main tank. Most of the time that works out. But new shrimp can carry hitchhikers, arrive stressed from shipping, or come with water and plants carrying pests. A short stay in a separate tank lets you catch those problems before they reach a colony you've spent months building.
Why quarantine shrimp?
- Hitchhikers on the shrimp. Dwarf shrimp often carry tiny attached organisms. In a 2023 study, researchers imported 900 Neocaridina davidi from Taiwan and found that about three-quarters hosted at least one of the recorded epibionts, such as the flatworm Scutariella japonica and the worm Holtodrilus truncatus. Farm-pond shrimp carried the most; aquarium-bred shrimp the fewest.
- Pests in the bag. Water, moss and plants that arrive with shrimp can bring planaria, hydra or pest snails. See planaria and hydra.
- Weak or dying shrimp. Shipping is hard on shrimp. Losses in the first days are easier to understand, and less worrying, in a separate tank.
- Protecting new shrimp. If your main tank has an active problem, a quarantine tank keeps the newcomers out of it while you sort it out.
What you need
The Merck Veterinary Manual describes a simple home quarantine setup for fish: an inexpensive 10-gallon tank, a sponge filter, a small air pump and a heater, with nets and siphon hoses kept only for that tank. For dwarf shrimp, a 5 to 10 gallon tank is plenty. Add:
- A seeded sponge filter. Merck suggests running the sponge in an established, healthy tank beforehand so it carries nitrifying bacteria. For shrimp, a few weeks in your main tank's filter flow works well. See how to cycle a shrimp tank.
- Matched water. Fill it with water from your main tank or water prepared the same way, so the shrimp only adjust once.
- Cover and grazing. A clump of moss or a few leaves gives shelter and biofilm. A bare bottom makes it easier to spot problems.
- A heater if needed to hold the same temperature as the main tank. See shrimp tank temperature.
How to quarantine new shrimp, step by step
- Acclimate into the quarantine tank, not the main tank. Follow how to drip acclimate shrimp, and don't add the bag water.
- Look at each shrimp closely in a clear cup under good light, ideally with a magnifier. Note anything odd on the head, gills or legs.
- Keep the first days calm. Low light, light feeding, and no large water changes.
- Check daily. Count shrimp, remove any dead ones quickly, and watch for the warning signs below.
- Check molts. Researchers note that damage from attached organisms shows up on shed molts, and that most attached organisms come off with the molt but can climb back onto the shrimp. A few molts in quarantine tell you a lot.
- Test the water a couple of times a week; a small tank can drift quickly.
- Move them over after the quarantine period if there have been no ongoing losses and the shrimp are eating, molting and behaving normally. Catch them with a net or cup and leave the quarantine water behind.
How long to quarantine shrimp
| Approach | Length | Notes |
|---|---|---|
| Short observation | About 2 weeks | Catches most shipping losses and gives time for a molt or two. The 2023 epibiont study observed imported shrimp in quarantine tanks for two weeks. |
| Common shrimp-keeper practice | 2 to 4 weeks | Enough time for pests from bag water or plants to show up. |
| Fish standard | 30 days or more | The Merck Veterinary Manual's minimum for fish, and a sensible choice for expensive shrimp or a large, valuable colony. |
What to watch for
- White, worm-like growths on the head or legs. Tiny flatworms such as Scutariella live mostly in the gill chambers and around the head. Their eggs and the damage they cause can show up on molts.
- White fuzz on the shell. This can be attached ciliates, which the same study found on many imported shrimp.
- Tiny white or flat worms on the glass or fine "threads" with tentacles. These may be planaria or hydra. Some white worms are harmless; see white worms in a shrimp tank.
- Ongoing deaths after the first few days, especially around molting. See shrimp dying after molting.
What not to do
- Don't dose fish medications as a precaution. Many contain copper, which is toxic to shrimp. See is copper toxic to shrimp.
- Don't share nets, hoses or buckets between the quarantine and main tank without rinsing and drying them.
- Don't treat routinely. Researchers mention brief salt baths for removing attached worms, but any dip stresses shrimp. If you see a problem, research the specific organism before treating.
- Never release shrimp, plants or tank water into the wild. Released aquarium shrimp and the organisms they carry have become established outside their native range, including in Europe.
If you can't quarantine
- Buy from a source you trust, and ask how the shrimp were kept.
- Inspect the shrimp in a cup before adding them, and don't add bag water.
- Rinse or quarantine plants and moss separately, or buy tissue-culture plants. See best plants for a shrimp tank.
- Watch the main tank closely for the first few weeks.
Track it
Log the quarantine tank's GH, KH, TDS and temperature next to your main tank's on the free Water Parameter Log printable, along with daily counts and any molts. You'll see at a glance whether the two tanks match before you move the shrimp over.
Frequently asked questions
Do you need to quarantine shrimp?
It isn't required, but it is a cheap way to protect an established colony from hitchhiking pests, attached organisms and shipping losses. It matters most for expensive shrimp or a large colony.
How long should I quarantine new shrimp?
Many shrimp keepers use 2 to 4 weeks. The Merck Veterinary Manual gives 30 days as a minimum for fish, which is a cautious choice for valuable shrimp.
Does a quarantine tank need to be cycled?
Yes. Seed the sponge filter in your main tank for a few weeks first so the quarantine tank can handle waste from the new shrimp.
Can I quarantine shrimp in a bucket or jar?
For a short time, with an air stone and a seeded sponge, yes, but a small cycled tank is far more stable. Small volumes drift quickly in temperature and water quality.
What are the white things on my new shrimp's head?
They may be tiny attached flatworms such as Scutariella, which are common on traded dwarf shrimp. Watch them through a few molts in quarantine before moving the shrimp.
Should I treat new shrimp with medication?
Not as a precaution. Many fish medications contain copper, which is toxic to shrimp, and dips stress them. Identify a specific problem first.
Sources: Merck Veterinary Manual, Management of Aquarium Fish (quarantine and biosecurity: 30-day minimum for fish, dedicated equipment, a 10-gallon home quarantine tank with sponge filter, air pump and heater, seeding the sponge in an established tank); Maciaszek et al. (2023), Epibiont cohabitation in freshwater shrimp Neocaridina davidi, Animals 13(10):1616 (about three-quarters of 900 imported shrimp hosted epibionts; microhabitats; molting; two-week quarantine observation; salt baths; risks of release); Shrimp Tank Hub's acclimation, cycling and pest guides.