Sulawesi shrimp care
Sulawesi shrimp are a group of Caridina from the ancient lakes of Sulawesi in Indonesia, best known through the cardinal shrimp (Caridina dennerli): red with white spots and white "socks." They are some of the most striking freshwater shrimp you can keep, and some of the hardest. Their water is unusual (warm, soft and alkaline all at once), and they depend on a tank that has had a long time to grow biofilm and algae.
Which shrimp are "Sulawesi shrimp"?
Sulawesi's highland lakes, Lake Poso and the Malili lake system (Matano, Towuti, Mahalona, Masapi and Lontoa), hold shrimp and snails found nowhere else. The ones seen most in the hobby:
| Shrimp | Lake | Notes |
|---|---|---|
| Cardinal shrimp (Caridina dennerli) | Matano | The most often available and, per Practical Fishkeeping, the easiest of the three to keep. The one to start with. |
| Sulawesi harlequin shrimp (Caridina woltereckae) | Towuti | The smallest, barely 20 mm, with an intricate red pattern. Not the marine harlequin shrimp. |
| Yellow-cheek shrimp (Caridina spinata) | Towuti | The most difficult; Practical Fishkeeping says even very experienced keepers struggle to keep it alive. |
Practical Fishkeeping's author kept these three together, since their needs are similar, and knew of no reliable reports of them crossing. Don't put them in a tank with bee, tiger or cherry shrimp: the water those shrimp need is very different. See Caridina vs Neocaridina.
Water parameters
| Parameter | Target | Notes |
|---|---|---|
| Temperature | About 27–28 °C (81–82 °F) | The lakes stay around 27 °C or warmer from surface to bottom. This is warmer than any common dwarf shrimp, so you need a reliable heater. |
| pH | About 7.8–8.5 | Alkaline. The lakes run around pH 8.5 (other readings are lower), and Dennerle's Sulawesi salt targets 7.8–8.5. |
| GH | About 6–7 °dH | Soft for such a high pH. Practical Fishkeeping cites the lakes at 4–8 °GH. |
| KH | About 2–5 °dKH | Enough carbonate to hold the pH up; the lakes are cited at 3–5 °KH. |
| Ammonia / nitrite | 0 | Fully cycled and mature before any shrimp go in. |
Getting soft and alkaline water is the hard part, because most water is either soft and acidic or hard and alkaline. Higher pH and temperature also make any ammonia more toxic, so the tank has to stay clean. See shrimp tank pH and ammonia and nitrite in a shrimp tank.
Making Sulawesi water
- RO plus Sulawesi salt. The usual route: mix a Sulawesi-specific remineralizing salt into RO water. These salts are made for RO water and won't soften hard tap water. Practical Fishkeeping's author preferred the "8.5" version of the salt over the "7.5." See remineralizing RO water.
- Soft tap water. If your tap water is already soft, it can be adjusted instead. Practical Fishkeeping's author started with aged tap water (pH 7.4, 5 °GH, 2 °KH), raised GH to 7 with a GH+ shrimp mineral, and raised KH and pH with small, measured amounts of baking soda, reaching about pH 8.4.
- Mix new water ahead of time, check pH, GH, KH and TDS, and match the temperature before it goes in. See shrimp GH and KH explained and shrimp TDS explained.
Tank setup
- Size: they are small enough for a nano tank (about 15 liters and up), but Practical Fishkeeping's author was advised they do better in larger groups and chose a bigger tank. A larger tank is also easier to keep stable.
- Substrate: sand or fine gravel. Practical Fishkeeping says standard shrimp soils must not be used, because they lower the pH. See best substrate for shrimp.
- Rock: a rocky layout, such as lava rock, gives a large surface for biofilm and algae, and recreates the rocky lake habitat where cardinals live.
- Filtration: a mature air-driven sponge filter gives gentle flow and a grazing surface; any power filter needs a fine pre-filter. See shrimp-safe filters and quiet air pumps.
- Heater: a dependable one that holds 27–28 °C with little swing. See nano shrimp tank heaters.
- Light: enough to grow a film of algae on the rocks; see shrimp tank lighting.
Mature the tank first, for longer than usual
The Sulawesi lakes are nutrient-poor, and the shrimp graze diatoms, algae and detritus. Practical Fishkeeping's author lost almost all of a first group within a week and named adding them too early, before there was enough biofilm and algae to graze, as a key mistake. A typical couple of weeks of maturing is not enough; plan on much longer, until the rocks and glass carry a visible coat of growth. Seeding rocks in an established tank with algae can speed this up. See how to cycle a shrimp tank and algae in a shrimp tank.
Buying and acclimating
- Look for captive-bred stock. The IUCN Red List assesses the cardinal shrimp as Critically Endangered (Possibly Extinct in the Wild). Tank-bred shrimp also tend to be bolder and cope better than wild-caught ones, which arrive stressed and hungry.
- Avoid cold shipping. Practical Fishkeeping's author traced early losses partly to a winter delivery that arrived below 20 °C, and other keepers reported the same.
- Drip acclimate slowly; Sulawesi shrimp are sensitive to sudden changes. See how to drip acclimate shrimp.
- Expect the first two weeks to be the risky part. Shrimp that get through them usually settle.
Feeding
At first, Sulawesi shrimp live almost entirely on the tank's biofilm and algae. Over time they can learn to take small amounts of fine powdered foods such as spirulina or fry food. Feed tiny amounts and don't overfeed: leftovers foul warm, alkaline water fast. Sulawesi Tylomelania snails can clean up leftovers and suit the same water. See what shrimp eat.
Water changes
Use small changes with pre-mixed water matched for temperature, pH and TDS. Practical Fishkeeping recommends dripping replacement water back in slowly, which "could save many lives." See shrimp tank water changes.
Behavior and breeding
Sulawesi shrimp are skittish. In small numbers they spend most of their time hiding, so a larger group and plenty of rock help. Unlike Amano shrimp, they are fully adapted to fresh water: their young develop without salt water, so they can breed in the aquarium. Cardinal shrimp carry relatively large eggs for their size. See berried shrimp care and baby shrimp care.
Are Sulawesi shrimp right for you?
Practical Fishkeeping is blunt: if you have never kept shrimp before, they are not for you. Try them only after keeping and breeding shrimp for years, and once you are comfortable holding unusual water parameters steady. Build experience first with cherry shrimp, then tiger shrimp or crystal red shrimp.
Track it
Log temperature, pH, GH, KH and TDS on the free Water Parameter Log printable. With Sulawesi shrimp, a small drift is worth catching early.
Frequently asked questions
What temperature do Sulawesi shrimp need?
About 27–28 °C (81–82 °F). The Sulawesi lakes stay around 27 °C or warmer all the way down, so a reliable heater is essential.
What pH do cardinal shrimp need?
Alkaline water, roughly pH 7.8–8.5, while staying fairly soft at about 6–7 GH. Most keepers use RO water with a Sulawesi-specific salt.
Can I use shrimp soil for Sulawesi shrimp?
No. Active shrimp soils lower the pH, which is the opposite of what Sulawesi shrimp need. Use sand, fine gravel or another inert substrate.
Are Sulawesi shrimp good for beginners?
No. Practical Fishkeeping advises keeping and breeding other shrimp for years first. Their warm, soft, alkaline water and dependence on a long-matured tank make them one of the hardest shrimp to keep.
Can Sulawesi shrimp live with cherry or crystal red shrimp?
Not well. Cherry, crystal and tiger shrimp need very different water, so Sulawesi shrimp need their own tank.
Do Sulawesi shrimp need salt water to breed?
No. Unlike Amano shrimp, they are fully adapted to fresh water, and their young develop in the aquarium.
What do cardinal shrimp eat?
Mostly biofilm, diatoms and algae growing in a mature tank. Over time they may take small amounts of powdered foods such as spirulina; avoid overfeeding.
Sources: Practical Fishkeeping (Gabor Horvath), The jewels of Sulawesi (Lake Poso and Malili lakes; oligotrophic; lakes over 27 °C top to bottom, 4–8 °GH, 3–5 °KH, pH 8.5; Caridina fully adapted to fresh water, young need no salt water; early losses from cold shipping and adding shrimp before enough biofilm and algae; inert substrate, shrimp soils lower pH; lava rock; tap water adjusted to 7 °GH and about pH 8.4, or RO plus Sulawesi salt, 8.5 version preferred; sponge filter; heater holding 27–28 °C; cardinal from Lake Matano, harlequin and yellow-cheek from Lake Towuti; cardinal easiest, harlequin about 20 mm, yellow-cheek hardest; skittish, tank-bred bolder; first two weeks; powdered foods; Tylomelania; drip water changes; not for keepers new to shrimp); Practical Fishkeeping, An introduction to shrimp (Sulawesi Caridina need relatively soft, about 6 °dH, alkaline, above pH 7.5, very warm water; not for novices); Practical Fishkeeping, Review: Shrimp King salts from Dennerle (Dennerle Sulawesi salt for RO water, pH about 7.8–8.5 and 6–7 °dH); IUCN Red List, Caridina dennerli (von Rintelen 2018 assessment) (Caridina dennerli Critically Endangered, Possibly Extinct in the Wild). The ammonia note, target table and stocking order are Shrimp Tank Hub's.