Reference

Shrimp water parameters: GH, KH, pH and conductivity

Four values really count. Here you can find out what they are and what you do if there are deviations.

Written by Valentin Fischer, aquarist and operator of Garnelenfischer
Published on 09.09.2026 · Last checked for content on 14.09.2026

For Neocaridina, exactly four values count in everyday life. Everything else is fine tuning. Here is what each value means, where it should be and what you do if it doesn't fit.

The four values at a glance

There are also two values that are not target values, but alarm values: Nitrite must be at 0 mg/l, ammonium too. Both are deadly in trace amounts. Nitrate may rise to around 25 mg/l.

GH: the building material

Total hardness supplies the calcium and magnesium a shrimp needs for its new shell at every moult. Below 4 °dGH, moulting often fails and the animal gets stuck in its old shell. The well-known white ring across the body is a sign of this.

In most Swiss municipalities the tap water is between 10 and 25 °dGH. This is ideal for Neocaridina and does not need to be treated. Only in soft regions such as parts of Ticino or in Alpine valleys is a mineral salt for invertebrates worthwhile to get 6 to 8 °dGH.

KH: the buffer

The carbonate hardness keeps the pH value stable. With KH under 2, the pH can crash overnight. With KH over 15, the water has a very strong buffer, which Neocaridina can still withstand, but bee shrimp cannot. A KH from 4 to 10 is the quietest area.

pH: mostly not an issue

Neocaridina live easily between 6.5 and 8.0. If there is enough KH, the value sets itself and stays there. Actively tinkering with the pH is unnecessary and usually harmful because the value fluctuates. Peat, soil and lots of leaves lower the pH, limestone and shell sand raise it.

Conductivity: the most important value when transferring shrimp

The conductivity (µS/cm) measures all dissolved salts together. The range 200 to 800 is sufficient for keeping. It is crucial when moving animals: a jump of more than about 100 µS/cm at once is stressful. That's exactly why the Settling in dripped over hours rather than adjusted in minutes.

A conductivity meter costs around CHF 20 and is the most useful purchase after a GH/KH test if you keep shrimp from different sources together.

How you measure

• Droplet testing for GH, KH and nitrite. More accurate than strips, cost around CHF 40 together and last for years.
• Test strips are sufficient for a rough control, but are unreliable with KH and nitrite.
• Conductivity measuring device (TDS meter), within seconds, ideal before every move.

Measuring rhythm in the retracted tank: once a month GH, KH and nitrite. After every change (new substrate, new roots, different water change) additionally.

Look up your tap water

Every Swiss water supplier publishes an annual drinking water analysis, usually as a PDF on the municipal website. This contains total hardness (often in French degrees of hardness °fH, conversion: °fH divided by 1.79 gives °dGH), nitrate and conductivity. For the aquarium, this analysis is a good starting point; Your own test still makes sense because house cables can change the values.

Sources and last update

All specialist sources accessed on 11 September 2026. The target areas in this text are the fisherman's husbandry recommendations from his private husbandry, not study results. Where a source says something different than what is recommended here, it is expressly stated.

On unity with nitrate. The specialist source mentioned below states up to 25 mg/l Nitrate nitrogen (N-NO₃) as acceptable and from 100 mg/l N-NO₃ as noteworthy. Aquarium tests, on the other hand, show nitrate (NO₃). 25 mg/l N-NO₃ corresponds to around 110 mg/l NO₃. Our recommendation of 25 mg/l nitrate is therefore significantly stricter than the value of the source. We do not convert, but state both values in their own unit.

• U.S. Fish and Wildlife Service (2025): Cherry Shrimp (Neocaridina davidi) Ecological Risk Screening Summary. March 2025, revised April 2025, web version dated 13 June 2025. Citing Prati and others (2024), it reports 14 to 30 °C, pH 6 to 8.2 and total hardness of 0 to 27 for captive breeding. This is a measured tolerance range, not a care recommendation, and is wider than ours. fws.gov
• Kubitza, F. (2026): Water quality impacts on health and performance of fish and shrimp, Part 3: The nitrogenous compounds ammonia, nitrite and nitrate. Global Seafood Alliance, 6 July 2026. The toxic proportion of ammonia in total ammonium rises sharply with the pH value: at 28 °C, according to this source, it is 0.71 percent at pH 7.0, 6.6 percent at pH 8.0 and 41.7 percent at pH 9.0. globalseafood.org
• Tropea, C., Stumpf, L., López Greco, L. S. (2015): Effect of temperature on biochemical composition, growth and reproduction of the ornamental red cherry shrimp Neocaridina heteropoda heteropoda. PLOS ONE 10(3), e0119468. 24, 28 and 32 °C were tested. The study names 28 °C as the optimum for rearing; at 32 °C, all females that reached sexual maturity and mated lost their eggs. doi.org
• The hardness values of the Swiss suppliers including the date of retrieval and the conversion between French and German hardness are in the guide Swiss tap water for shrimp.