TDS Calculator
Estimate Total Dissolved Solids (TDS) from GH/KH or conductivity, and check which shrimp species fit your water.
Estimated TDS
266 ppm
Range: 214–339 ppm (estimate excludes trace ions).
Conductivity
532 µS/cm
Reverse estimate via 0.50 (NaCl) scale.
Water character
Moderate
Rough qualitative bucket based on NaCl-equivalent TDS.
Shrimp species fit
Compares your TDS to colony-stable ranges (NaCl scale). Always acclimate slowly across TDS shifts of more than 30–50 ppm.
Neocaridina (Cherry, Blue Dream, Yellow)
Neocaridina davidi
- TDS
- 150–300
- GH
- 6–12
- KH
- 2–8
Hardy in moderately hard tap water. Avoid drops below 100 ppm TDS during water changes.
Caridina — Crystal Red / Black
Caridina cantonensis
- TDS
- 100–150
- GH
- 4–6
- KH
- 0–2
Requires RO + remineralizer (e.g. Salty Shrimp GH+). Low KH for stable acidic pH.
Caridina — Taiwan Bee / Pinto
Caridina cantonensis var.
- TDS
- 110–140
- GH
- 4–6
- KH
- 0–1
Demanding selectively-bred lines. Stability matters more than exact numbers.
Sulawesi (Cardinal, Harlequin)
Caridina dennerli / spp.
- TDS
- 120–180
- GH
- 4–8
- KH
- 4–8
Warm (27–30 °C), alkaline (pH 7.8–8.4). KH and pH must stay high — opposite of Caridina cantonensis.
Amano shrimp
Caridina multidentata
- TDS
- 150–400
- GH
- 6–15
- KH
- 2–10
Very tolerant. Algae-eating workhorse for planted tanks.
Ghost / Whisker shrimp
Palaemonetes paludosus
- TDS
- 150–400
- GH
- 5–15
- KH
- 3–12
Hardy but can be nippy toward small fish or other shrimp.
Related Guide
TDS is the cheapest and most informative single number for shrimp tanks. Track it weekly with a calibrated pen and aim for < ±10% week-over-week drift.
When mixing RO and tap, use a remineralizer (e.g. Salty Shrimp GH+) targeted at the species’ preferred GH; KH then follows from your buffer choice (zero KH for active soil + Caridina, low KH for Neocaridina).
Big TDS swings during water changes kill more shrimp than slightly wrong absolute values. Drip-acclimate any shrimp moving across more than 30–50 ppm of TDS.
FAQ
Why does TDS matter for shrimp?
Shrimp osmoregulate across their cuticle and are far more sensitive to abrupt swings in dissolved-ion concentration than most fish. Stable TDS is often the single biggest survival lever for Caridina lines.
Can I derive TDS exactly from GH and KH?
No. TDS counts every dissolved ion (sodium, chloride, fertilizer residues, dissolved organics). GH + KH are a lower bound only — use a TDS pen or conductivity probe for the real value.
What conductivity-to-TDS factor do you use?
The calculator lets you switch between the NaCl scale (0.50), which consumer aquarium pens like the HM Digital TDS-3 read on, and the 442 / “natural water” scale (0.70) common on well-water meters. Shrimp species ranges below are NaCl-scale; the calculator converts automatically when you change scales.
Where do the species ranges come from?
Conservative colony-stable ranges aggregated from common shrimp-keeping guidance. They are starting points, not laws — your specific line may tolerate more.
Did this answer your question?
TDS from GH/KH is a lower-bound estimate that excludes non-hardness ions. Conductivity-to-TDS uses the 0.5 NaCl scale that consumer aquarium pens read on; meters set to the 442 scale read about 40% higher for the same water. Results are estimates based on general guidelines. Individual species may have specific requirements.