Best substrate for shrimp: cherry vs crystal
The single biggest substrate decision is which shrimp you keep. Neocaridina (cherry, blue dream, and other color morphs) do well in neutral-to-slightly-hard water and are happy on almost any inert gravel or sand. Caridina (crystal red, crystal black, and other bee shrimp) are usually kept in soft, slightly acidic water, and most keepers use an active (buffering) aquasoil plus RO water to get there.
This guide compares published manufacturer claims and recurring owner reports. We haven't run these substrates side by side ourselves.
| Substrate | Type | Effect on water | Best for | Owner-reported trade-offs |
|---|---|---|---|---|
| Inert gravel or sand (e.g. CaribSea Eco-Complete) | Inert | Little to none (check that it doesn't contain limestone or coral, which raise hardness) | Neocaridina | Lasts indefinitely; plants need root tabs. |
| Fluval Stratum | Volcanic soil, mild buffering | Maker says it "supports a neutral to slightly acidic pH" and reduces KH | Neocaridina, planted tanks; budget Caridina setups with care | Inexpensive and plant-friendly; owners often report the buffering fades within a few months. |
| ADA Aqua Soil Amazonia | Active aquasoil | Owners report pH roughly 6.0–6.8 | Caridina | Strong reputation; expensive; leaches ammonia when new, so needs a full cycle. |
| Controsoil | Active aquasoil | Owners report pH around 6.2–6.6 | Caridina on a budget | Cheaper than ADA; some keepers report buffering fading sooner. |
Cherry shrimp (Neocaridina)
You don't need a special substrate. Most tap water that suits community fish will suit cherries. Active soils can actually work against them in soft tap water by pulling pH and KH lower than they prefer. Dark substrates are popular because owners find they show off red and blue colors better, but that's aesthetics, not health.
Crystal and bee shrimp (Caridina)
The usual recipe in the hobby is an active soil, RO or RO/DI water, and a GH-only remineralizer. Hard tap water with KH of a few degrees or more exhausts the soil's buffering much faster. Shrimp-focused references commonly cite 12–18 months of useful buffering from RO water, after which pH and KH drift up toward your source water and the soil needs replacing.
How to choose: four questions
- Which shrimp? Neocaridina are flexible; Caridina usually need soft, acidic water, which points to active soil.
- What's your source water? Test your tap GH and KH (see our test kit guide). Hard tap water exhausts active soil quickly, so Caridina keepers generally use RO water.
- Live plants? Aquasoils contain nutrients for rooted plants; inert gravel or sand needs root tabs for heavy root feeders.
- How long do you want it to last? Inert substrate is effectively permanent. Active soil's buffering is finite and eventually needs replacing.
How much substrate do I need?
Multiply length × width × desired depth (in inches), then divide by about 231 to get gallons of volume, or work in centimeters and divide by 1,000 for liters. Most aquasoil is sold by volume in liters, while gravel is usually sold by weight. For a standard 5-gallon tank at 1.5–2 inches deep, many keepers report needing roughly 3–4 liters of aquasoil. Check the maker's coverage chart, and buy a little extra for sloping the back.
Setting up active soil for Caridina
- Add the soil dry and fill slowly over a plate or plastic bag to limit clouding.
- Use RO or RO/DI water remineralized with a GH-only product suited to Caridina.
- Cycle fully. New aquasoils commonly leach ammonia for several weeks; frequent water changes during this period are common practice.
- Test until ammonia and nitrite stay at zero and pH and KH have settled where you want them, then add shrimp.
Substrate color, grain size and plants
Beyond water chemistry, the physical properties of a substrate matter. Grain size affects how much debris settles between grains and how easily roots spread: fine sand packs tightly, while 2–5 mm granules leave more space. Fluval, for example, lists regular Stratum at roughly 3–5 mm granules and its Bio-Stratum at 1–3 mm. Many shrimp keepers like aquasoil's porous granules because shrimplets can shelter between them, which Fluval also mentions in its own marketing.
Color is mostly aesthetic, but it's a common topic in owner discussions. Dark substrates are often said to make red and blue shrimp look more saturated, while light sand makes them easier to spot and count. Shrimp are widely reported to adjust their coloration somewhat to their surroundings.
Plants change the equation. Stem plants and mosses, which shrimp keepers love, don't depend much on substrate nutrients. Rooted plants such as crypts and swords do better in aquasoil or with root tabs in inert substrates.
When to replace active soil
The clearest sign is drift: pH and KH slowly rising toward your source water even though your water-change routine hasn't changed. Granules breaking down into mud is another sign. Replacing substrate in an established shrimp tank is disruptive, so many keepers plan for it by moving shrimp to a temporary tank, or by layering fresh soil over the old when partially refreshing a scape. Either way, treat the new soil as a fresh cycle and test before returning the shrimp.
Common mistakes
- Using active soil for Neocaridina in soft tap water. The soil can drive pH and KH lower than cherries prefer.
- Adding shrimp too soon. Ammonia from new aquasoil is a commonly reported cause of early losses.
- Using hard tap water with active soil. It shortens the soil's buffering life significantly.
- Choosing decorative gravel with limestone or shell. These raise GH, KH and pH, which suits neither Caridina nor most planted tanks. A vinegar fizz test can reveal calcareous gravel.
- Deep-vacuuming aquasoil. It breaks granules into mud. Hover the siphon over the surface instead.
FAQ
What is the best substrate for cherry shrimp?
Almost any inert substrate works for cherry shrimp: plain gravel, sand or an inert planted substrate. Active soils aren't necessary and can lower pH more than cherries prefer in soft water.
Do crystal red shrimp need active substrate?
Most Caridina keepers use active substrate because it buffers water toward the soft, slightly acidic range these shrimp are typically kept in. Some keepers manage without it using carefully prepared RO water, but active soil is the norm.
Is Fluval Stratum good for shrimp?
Fluval markets Stratum as suitable for shrimp and says it supports neutral to slightly acidic pH. Owners frequently report its buffering effect is milder and shorter-lived than premium aquasoils, so it's often recommended for Neocaridina and planted tanks rather than long-term Caridina setups.
How long does aquasoil last?
Shrimp-focused references commonly cite 12–18 months of buffering with RO water, sometimes longer. Hard water and aggressive vacuuming shorten it. When pH and KH start drifting up, the buffering is exhausted.
Can I mix sand and aquasoil?
Some keepers use sand in the foreground and soil elsewhere, but the two tend to mix over time. Using a divider or keeping them in separate zones helps.
Do I need to rinse aquasoil?
Most manufacturers advise against rinsing aquasoil, as it can break down granules. Inert gravel and sand usually do benefit from rinsing.
Our take
Keeping Neocaridina? Use an inert substrate you like the look of and spend the savings on plants. Keeping Caridina? An active soil is the norm. ADA Amazonia has the strongest long-term reputation, and Controsoil is the frequently suggested cheaper alternative. Fluval Stratum is a reasonable middle ground for planted tanks, but don't rely on it to hold low pH for long.
Sources: Fluval Stratum product pages; The Shrimp Guide, "Active substrates for Caridina explained"; The Planted Tank forum threads on Amazonia alternatives (2024–2026); owner reviews of Fluval Stratum. Specs and claims checked October 2026.