How to Raise Sulawesi Shrimplets

What does it take to raise Sulawesi shrimplets? Mostly work you’ve finished before they exist: grazing surfaces that are already mature when the brood hatches, warm alkaline water that stays steady afterwards, and as little change as possible once the shrimplets are out. Nothing you add later stands in for a tank that was already feeding itself. And the most common way to lose a brood? Starting to feed and fiddle because you can finally see babies.

Sulawesi shrimplets hatch ready to graze, so skip the larval setup

You don’t need a larval setup, because Sulawesi lake shrimp (Caridina spp.) carry a few large eggs, the pattern that goes with young that hatch ready to graze. In the 2009 systematic revision of the group, ovigerous Caridina dennerli females were recorded carrying 8-14 eggs each across 7 females. Those eggs measured 1.0-1.2 x 0.5-0.7 mm, against an examined adult carapace length of 1.5-3.4 mm.¹ Other species in the same revision run higher, and the spread across the group is wide enough that no single brood figure describes it. The shape of the strategy holds, though: a small number of very large eggs for the size of the animal carrying them.

Across freshwater shrimps generally, that egg pattern goes with direct or abbreviated development, where the young hatch as a postlarva or pass through only a few nonfeeding larval stages.² Nobody has published a description of it for a Sulawesi species yet, so treat it as the direction the biology points.

Here’s the part that changes what you buy. You aren’t raising larvae. There’s no window when the shrimplets need something the adults don’t, and no food you can add that the tank wasn’t already making. They need the water the adults need, held steadier, and a surface that’s already producing something to eat on the day they arrive. That surface, not a food jar, is what answers what baby Sulawesi shrimp eat, and it has to be there before the brood hatches.

Set the tank up before the Sulawesi brood hatches, not after

Get the tank ready while the female is still carrying, because a tank that has just finished cycling and a tank that’s ready for shrimplets aren’t the same thing. Only one of them shows up on a test kit. Zero ammonia and zero nitrite tell you the filter works. They tell you nothing about whether there’s anything on the rock to eat. Food in a dish is food a very small animal has to find, crossing open ground to reach it. Food growing on the rock is already where the animal is, and that’s the one you can build ahead of time.

So use the brooding weeks for that, not for shopping. One keeper’s female arrived already carrying eggs, and about three weeks later the eggs were gone and there were little shrimplets instead. That’s roughly the window you’re working with. Keep the tank inside the group range the whole time.

Hold those steady instead of hunting for a better point inside them. Lake Towuti, one of the Malili lakes this group comes from, sits at roughly 82°F (28°C) year round, in a tropical climate whose monthly air temperatures barely move.³ These animals were shaped by sameness, not by an optimum. A tank parked anywhere inside the band and left alone will do better than one being nudged toward a number somebody published.

A rearing tank also has no fish in it. Species described as generally lower risk with adult shrimp will still take shrimplets, and there’s no stocking level at which that stops being true. If you want young from a group, the fish come out before the brood is due, not after you notice the count dropping.

Timing the group matters as much as timing the tank. Adding shrimp during a rearing window means repeated acclimation events and bioload steps in a tank whose whole job is to stay unchanged. Bring in the tank-bred Sulawesi shrimp you want as one order, and let the group settle before you start looking for broods. Getting that timing right before the group even goes in is the core of how to breed Sulawesi shrimp.

Before you count on a brood surviving, the tank should pass every check below.

• Ammonia and nitrite read zero on two tests a week apart, with the tank stocked and being fed normally.
• Visible biofilm and soft algae have colonized the rock and the glass, not just the filter.
• pH and TDS read the same across two weeks with no correction from you.
• The heater holds the temperature inside the band with no daily swing you can measure.
• Hardscape is porous and stacked so there are sheltered surfaces a shrimplet can graze without crossing open ground.
• Not ready: a tank running a few weeks on a bacterial starter with clean glass and nothing growing on the stone yet.

Build the grazing surface Sulawesi shrimplets actually eat from

The rock is the food supply, so treat surface area as a stocking decision. Porous, inert hardscape stacked into a structure with light reaching most of it gives you far more grazing area per liter than a flat layout. It also gives the shrimplets somewhere to sit while they use it. A moderate photoperiod is part of the same job, since part of what you’re growing is algae.

Whatever you do, don’t bury that surface. Deep substrate beds and heavy vacuuming work against each other, and both work against the shrimplets, because the film you remove when you clean is the thing they eat. Keep the substrate shallow and inert, and leave the rock alone.

Plant cover outperformed bare stone in the only controlled trial

A 2025 rearing trial raised Caridina dennerli from an average starting total length of 1.445 cm under four combinations of feed and shelter. The pellet groups ran for 30 days and the bacterial starter groups for 37 days. Commercial pellets with plant cover gave both the highest growth and the highest survival of the four.⁴

Read it carefully before you act on it. The trial started with juveniles already over a centimeter long, not with hatchlings, and it varied feed and shelter, not water. Its survival percentages describe that setup and aren’t a rate to expect at home. What carries over is the comparison itself: living, finely divided cover beat bare stone on both measures, which is the biofilm lesson again from a different angle. The plant the trial used isn’t the point, and it isn’t sold everywhere, so check whether the plant you choose is permitted where you live before ordering it. A dense, fine-leaved moss does the same job in a warm alkaline tank and is easier to find.

Why feeding more after a hatch is what kills Sulawesi shrimplets

Extra food turns into ammonia, and in warm alkaline water more of that ammonia is in its toxic form. Total ammonia in water sits in balance between the ammonium ion and un-ionized ammonia, and the un-ionized form is the one that drives toxicity in aquatic animals. The ratio of un-ionized ammonia to ammonium in fresh water rises roughly tenfold for each single pH unit. It rises about twofold for each 10 degrees Celsius of warming between 0 and 30 degrees Celsius. High external un-ionized levels reduce or reverse diffusive gradients, so ammonia builds up in internal tissues and blood.⁵ Those relationships were worked out for freshwater aquatic life as a whole, not for Caridina, so use them for the chemistry and not as a threshold for your shrimp.

Now drop Sulawesi water into that relationship. This group is kept warm and alkaline because it has to be, not by preference. So the same milligram of waste does more damage in your tank than the identical test reading would in a cool, acidic one. That’s why a Sulawesi rearing tank is so unforgiving about food, and why the urge to start feeding the moment you see shrimplets works against you.

During a rearing window, feed the tank you had before the hatch, not a bigger one. Want to reach the shrimplets? Target the surface, not the water column. A very small amount of a fine powdered food placed onto the rock with a pipette lands where they already are. Anything still sitting there hours later was too much. If you can’t tell how much organic load a product adds, that’s a reason to skip it during a rearing window. Halving the dose doesn’t fix that.

Aerate a warm Sulawesi tank without pushing shrimplets around

Get the oxygen from the surface and the filter, not from current, because a warm tank holds less oxygen and current is what a shrimplet handles worst. Warm water is thin water where oxygen is concerned: cold water can hold more dissolved oxygen than warm water.⁶ So a tank running near the top of the Sulawesi band starts with less oxygen headroom than a cool shrimp tank with the same aeration. That’s before you add the extra biological demand of a warm, mature, heavily colonized system. Oxygen isn’t a detail on this page. It’s one of the two things you’re actively managing.

The awkward part is that the obvious way to add oxygen is more flow, and flow is what a newly hatched shrimplet copes with worst. So separate the two. Get the gas exchange from surface movement and from filter media with air passing through it, then aim the return so the water at rock level is barely moving.

Whatever filter you run, the intake has to stop being a hazard before the brood is due. A sponge over the intake, or sponge filtration on its own, removes the suction risk and adds grazing surface at the same time. Fit it in advance. The week you notice shrimplets isn’t a week you want to spend reaching into the tank to rearrange hardware.

Change and top off a Sulawesi rearing tank without shocking the shrimplets

Top off with pure RO water and make water changes small and matched, because those are two different jobs that call for two different waters. Mixing them up is a slow way to ruin a stable tank. Topping off replaces water that evaporated. A water change replaces water that’s still there.

Evaporation leaves the dissolved solids behind and concentrates them in the water that remains. That’s the mechanism the US Geological Survey describes for shallow groundwater in arid regions,⁷ and the same physics pushes a warm aquarium’s TDS up week by week. So top-off water is pure RO or RO/DI, never remineralized water, or the tank climbs out of its own range while every single top-off looks harmless. Small and frequent beats large and weekly, which is the one argument for an automatic top-off unit on a tank you’re trying to keep boring.

For the water changes themselves, change less, change slower and match before you pour. Alkalinity is what makes that possible. It’s the buffering capacity of a water body, its ability to neutralize acids and so keep pH fairly stable, and it comes from the bicarbonates, carbonates and hydroxides in the water.⁸ Let KH drift down and pH stops holding, and in this group pH is the parameter you can least afford to have moving. A good water change isn’t measured by its size. It’s measured by pH and TDS reading the same afterwards as before. So test both on the replacement water first, and add it slowly enough that the tank never registers the difference.

Prepare replacement water outside the tank

Mineral choice is a rearing decision as well as a setup one, because it decides what your replacement water can safely be. Sulawesi Mineral 8.5 doesn’t simply stir into RO water. The manufacturer states that it will almost totally dissolve if CO2 is added for a few days, which takes approximately 3-4 days at a regular quantity of about one bubble per second. The water must then be aerated with an air stone for at least three hours to expel the CO2.⁹

The 7.5 grade of the same range skips that step. The manufacturer states that it will almost totally dissolve within seconds and the water is ready for use immediately, and that it buffers the pH at around 7.5.¹⁰ Notice where that sits: at the bottom endpoint of the group range. So choosing between Sulawesi Mineral 7.5 or 8.5 is really choosing which end of the band your tank will live at, and that’s a decision to make before a brood is due.

Getting the mineral content right matters more during a rearing window than at any other time, because crustaceans take most of the calcium for a new shell from the water they live in.¹¹ A growing shrimp is building its next shell out of your GH. Hardness that quietly drifts down over the weeks a brood is growing isn’t a cosmetic problem.

Everything else about maintenance in this period is subtraction. Don’t vacuum the substrate, scrub the rock, net anything out or rearrange the layout to see better. Each of those removes grazing surface, releases trapped organics into warm alkaline water, or both.

Raising the temperature won’t grow Sulawesi shrimplets faster

Turning the heater up won’t give you bigger shrimplets sooner, so leave it where it is. It’s the lever almost everyone reaches for, which makes it worth closing off properly. Growth in these animals isn’t continuous. Freshwater prawns, like other crustaceans, have to cast the exoskeleton regularly in order to grow,¹² so size arrives in steps at each molt and not in between. Warming a tank shortens the gap between those steps, and that’s where the idea comes from.

Crab work suggests the step gets smaller too: lesser blue crabs reared warmer molted more often but grew less per molt, ending up smaller at each stage.¹³ That’s a crab and not a Caridina, so take it as the direction the effect runs.

Set against that you have the oxygen cost above and, at the top of the band, less margin for any mistake in feeding. The growth increments measured in the trial earlier on this page are the scale you’re working at either way. Pick a point inside 79-86°F (26-30°C) that your heater can hold without swinging, then stop touching it. Patience is the only accelerant that costs nothing.

How to read the first weeks after a Sulawesi hatch

Expect to see almost nothing at first, and treat that as no information either way. A structured, well grazed layout hides a very small animal very effectively. The urge to lift a rock and check is the most destructive thing you can act on in this period, and it tells you less than the test kit already does.

Read the tank, not the shrimp. Ammonia and nitrite staying at zero, pH and TDS flat week to week, and film growing back on any surface you disturbed all matter. So do adults behaving the way they did last week. All of that is more useful than any headcount you could make. If a problem sits at system level it’ll show on the test kit, and the adults are the animals you can actually watch for a change.

Some loss is normal, and a single body tells you nothing on its own. What separates ordinary attrition from a failing tank is coincidence: several losses in a short window, or losses that arrive alongside a measurement that moved, or alongside a change in adult behavior. In that case the fix goes to the measurement, made slowly, not to the shrimp. There’s no published survival figure for home-reared Sulawesi broods to measure yourself against. The only measured percentages belong to the controlled trial above, on larger juveniles, in a setup that isn’t yours. A single missing shrimplet means little, but a cluster of losses is the pattern why baby Sulawesi shrimp die actually looks for.

One thing not to do is treat. You can’t diagnose a cause from a shrimplet body. Medication safety depends on the exact active ingredients, the concentration and your water chemistry, not on what the label promises, and copper and several common fish treatments carry real risk to invertebrates. If you reach the point where you believe something needs treating, describe what you measured to a qualified aquatic vet or an experienced specialist first. Do that before you dose anything into a tank with a brood in it.

What the research says about raising Sulawesi shrimplets

Three of the studies behind this guide are on other animals, not on Sulawesi Caridina, so read them as the mechanism and not as a measurement of your tank. On development, a 2013 paper on shrimp life cycles reports that most completely freshwater species spawn large embryos with either direct or abbreviated larval development. The hatching stage is either a postlarva, which avoids the planktonic environment completely, or a few nonfeeding larval stages. Amphidromous species, whose life cycle runs between rivers and the sea, take the opposite route and spawn many small eggs that hatch at a much less advanced stage.² That’s a pattern across caridean shrimps, and no published description of a Sulawesi species’ development was available for this guide.

On shells, a 2012 paper on how crustaceans build them found that the major source of calcium used for exoskeleton calcification is exogenous, meaning the water the animal lives in, with food and stored reserves contributing less.¹¹ On temperature, previous laboratory and field experiments suggest that temperature affects both intermolt period and growth per molt in many crustaceans. Lesser blue crabs (Callinectes similis) reared at elevated temperatures showed a shorter intermolt period together with less growth per molt, ending up smaller at each instar. The authors add that if the pattern continued through the pubertal molt, elevated temperatures would result in a smaller size at maturity.¹³ That last point is their conditional and wasn’t measured.

References

13 Sources

1. Radiation of endemic species flocks in ancient lakes: systematic revision of the freshwater shrimp Caridina from the ancient lakes of Sulawesi, Indonesia, with the description of eight new species, The Raffles Bulletin of Zoology 57(2): 343-452, 2009.
2. Amphidromy in shrimps: a life cycle between rivers and the sea, Latin American Journal of Aquatic Research 41(4): 633-650, 2013.
3. Geomicrobiological Features of Ferruginous Sediments from Lake Towuti, Indonesia, Frontiers in Microbiology 7: 1007, 2016.
4. Effect of Using Different Shelter and Feed Types on Growth and Survival Rate of Sulawesi Endemic Ornamental Shrimps (Caridina dennerli), journal PDF, Jurnal Ilmiah PLATAX 13(1): 191-204, 2025.
5. Aquatic Life Ambient Water Quality Criteria for Ammonia, Freshwater, U.S. Environmental Protection Agency, Office of Water, April 2013.
6. Dissolved Oxygen and Water, U.S. Geological Survey Water Science School, updated August 24, 2026.
7. Chloride, Salinity, and Dissolved Solids, U.S. Geological Survey Water Resources Mission Area, March 1, 2019.
8. Alkalinity and Water, U.S. Geological Survey Water Science School, updated August 24, 2026.
9. Sulawesi Mineral 8,5, minerals and trace elements, SaltyShrimp manufacturer product information page.
10. Sulawesi Mineral 7,5, minerals and trace elements, SaltyShrimp manufacturer product information page.
11. Biomineralizations: insights and prospects from crustaceans, ZooKeys 176: 103-121, 2012.
12. Farming freshwater prawns, biology chapter, FAO Fisheries Technical Paper T428, Food and Agriculture Organization of the United Nations.
13. Elevated temperature induces a decrease in intermolt period and growth per molt in the lesser blue crab Callinectes similis Williams, 1966, abstract, Journal of Crustacean Biology 39(1): 22-27, 2019.