pH water test in drops, wide or narrow range
This drop test gives the pH in three ranges: from 3.0 to 10.0 to get a first reading of unknown water, from 6.0 to 7.6 or from 7.4 to 9.0 to monitor freshwater, a pond or an aquaponic system closely. Its reading is interpreted alongside the carbonate hardness, or KH, which stabilises the pH.
The summary
- What you receive: a reagent, the glassware and a colour chart, for about 50 measurements in the wide range or 80 in the narrow range.
- What you measure: pH from 3.0 to 10.0, or more precisely from 6.0 to 7.6 or from 7.4 to 9.0, in freshwater, in a pond and in seawater.
- What the number means: the scale is logarithmic. Between pH 7.5 and pH 8.5, your water becomes 10 times more alkaline.
- When to measure: always at the same time of day, and note it down. In a planted tank, the pH varies by several tenths between morning and evening.
- How to choose: the wide range screens unfamiliar water, while a narrow range tracks water whose zone you already know.
- Precautions: the reagent is alcohol-based, flammable and irritant; the reading is taken on a sample, never in the fish's water.
Liquid pH test, wide range or narrow range, for aquarium, pond and aquaponics
This drop test gives pH from 3.0 to 10.0 to place an unknown water, or finely from 6.0 to 7.6 or from 7.4 to 9.0 to monitor a tank, a pond or an aquaponic system, with 50 to 80 measurements. The reagent stays in the test tube, never in the fish's water, and each range has its own refill.
pH is the parameter you will measure most often, and its value must always be read alongside others. This test gives a number, in a wide range of 3.0 to 10.0 or in narrow ranges of 6.0 to 7.6 and 7.4 to 9.0, which does not tell you on its own whether your water is stable or whether it will stay so, since that stability depends on carbonate hardness. A correction made on the basis of pH alone can therefore cause a sharper swing than the imbalance it was meant to fix.
🔬 Wide range or narrow range
The wide range places unknown water at a glance, but its colour fields are spaced 0.5 units apart. The two fine versions narrow the colour chart to 1.6 units and are read in a comparator block: a second tube of untreated water, placed alongside, cancels out the water's own tint, which keeps the reading accurate in water slightly coloured by peat or by a treatment. The 6.0 to 7.6 version covers slightly acidic or neutral fresh water, and so most aquaponic systems, which you keep between 6.4 and 7.5. The 7.4 to 9.0 version covers alkaline fresh water, garden ponds and seawater, whose optimum is around 8.2.
Three mistakes that skew the pH reading
Read the result in daylight, with the test tube placed against a white background, because aquarium lighting skews the perception of yellows and greens. Keep to the 5 ml volume and the number of drops for your version, 5 for the wide range and 4 for the fine range, then wait 5 minutes for the wide range and 3 minutes for the fine range before comparing. Finally, take your sample from the middle of the water column, never just under the surface film.
📉 A logarithmic scale
The pH is a logarithmic scale: each unit is a factor of 10. Water at pH 7.5 is 10 times less basic than water at pH 8.5, and a difference of 0.5 already represents a ratio of 3. This is why a pH that shifts by one unit in a single evening puts your fish in serious difficulty, whereas the same change spread over 3 weeks is far better tolerated: sudden swings are what you must avoid above all. The article on pH regulation details the procedure.
In aquaponics, a trade-off
Nitrification is most efficient between 7 and 8, whereas roots absorb iron and phosphorus better below 7, so the pH is best kept between 6.4 and 7.5.
In a garden pond
The favourable range lies between pH 7.5 and 8.5, which the fine version, from 7.4 to 9.0, covers entirely.
In very soft water
Without a buffer, the pH drops on its own, sometimes below 6, where only the wide range still gives a reading.
After an addition
Correction product, fresh grow medium, limestone, peat: each one changes the value, though not always in the direction you would expect.
Measure the KH before correcting the pH
What keeps the pH stable is carbonate hardness, which absorbs the acids produced by nitrification. So buy the carbonate hardness test at the same time as this one: if the KH is high, a pH forced with a corrector returns to its equilibrium value within a few days, and if it is low, nothing buffers the water any more and the pH can drop suddenly. With both figures, you know which to correct, and in what order.
🕑 The time of measurement
In a planted volume, dissolved carbon dioxide makes the pH vary from hour to hour: by day photosynthesis consumes it and the pH rises, by night plants and bacteria release it and the pH falls. The swing commonly reaches several tenths of a unit between early morning and the end of the day. Always test at the same time of day and note it down; to find out the real swing in your set-up, take two readings on the same day rather than two a week apart.
🐠 pH and ammonium toxicity
The pH also determines the toxicity of ammonium. Dissolved ammonia nitrogen is split between the ammonium ion, which is only mildly toxic, and ammonia, which crosses the gills, and the proportion of ammonia rises with pH. At 25 °C, it represents about 0.6% of the ammonia nitrogen at pH 7, compared with 5.4% at pH 8: the same ammonium level is therefore nearly 10 times more dangerous in a pond at pH 8 than in a tank at pH 7. Always read your ammonium test alongside the pH from the same day, especially in summer, when temperature adds to the effect of pH.
🧤 An indicator in alcohol
The three pH reagents are coloured indicators dissolved in ethanol: they are flammable and irritate the eyes, but are not corrosive. The routine is the same as for all drop tests: take a sample from the tank, add drops to the test tube, read the result in daylight, and tip the sample down the sink. In aquaponics, pH is checked every week and after every correction, so the bottle gets used up faster than in an aquarium; the pH reagent refill is available for each of the three ranges and fits in the same case, to be kept away from flames and out of reach of children. If you correct the pH, also measure the carbonate hardness on the same day, since it is this that will tell you whether the correction will hold.
Technical specifications
Measuring pH
- Parameter measured
- pH, the acidity or alkalinity of the waterLogarithmic scale: a difference of one unit means a factor of 10 in actual acidity
- Measuring ranges
- 3.0 to 10.0, 6.0 to 7.6 or 7.4 to 9.0Depending on the version chosen. The wide range is for screening, the narrow ranges track water whose zone is known
- The colour chart fields
- No 0.5 step on the wide rangeOne field at 3.0, then in steps of 0.5 from 4.0 to 10.0. The fine-range strips carry a tighter graduation across 1.6 units
- Tests per kit
- Around 50 or 8050 on the wide range, 80 on the fine range
- Method
- Liquid reagent, colorimetric readingThe fine ranges are read in a comparator block that cancels out the water's own tint, the wide range without a reference
- Manufacturer references
- JBL 2410100, 2410300, 2410500In order: 3.0 to 10.0, then 6.0 to 7.6, then 7.4 to 9.0
The procedure
- Water volume
- 5 mlTaken from the middle of the water column. In the narrow ranges, a second 5 ml test tube serves as a blank
- The steps
- Rinse, fill, add reagent, shake, wait, readThe number of drops is calibrated for this volume and no other
- Waiting time
- 5 or 3 minutes5 minutes in the wide range, 3 in the fine range. An immediate reading gives a colour that is still changing
- Total time
- About 6 minutesHandling included
- Reading
- Colour chart, in daylightAquarium lighting shifts the perception of yellows and greens, and therefore the value read
- Water types covered
- Freshwater, seawater, pondFor a saltwater tank, the 7.4 to 9.0 range reads the useful zone around 8.2
Hazard labelling
- Signal word
- WarningAll three ranges carry the same marking
- Pictograms
- Flame and exclamation markGHS02 and GHS07
- Hazard statements
- H226, H319Highly flammable liquid and vapour, causes serious eye irritation, due to the ethanol
- Precautionary statements
- P101, P102, P303+P361+P353, P305+P351+P338, P501Keep the label for the doctor, children kept away, skin and eyes rinsed with water, dispose of according to local rules
- Precautions
- Away from flame, out of reachBottle recapped after each measurement
- Measured sample
- Poured down the sinkIt must never go back into the tank or into the system
To allow for in addition
- The test that goes with it
- A carbonate hardness testIt tells you whether your pH will stay stable, and it is the first thing to correct
- Reagent refill
- Reagent only, for each rangeThe colour chart and glassware for your range remain valid
- To raise the pH
- Potassium bicarbonateIt raises the KH, and so the stability of the pH, and supplies potassium to the crops
- Read with
- The ammonium testThe pH on the same day determines the proportion of toxic ammonia
14 further specifications are available in the detailed view.
In the box
- 1 bottle of pH reagent with child-resistant cap
- 1 colour chart specific to the chosen range
- 1 multilingual instruction leaflet, French included
- 1 graduated plastic test tube for the wide range, or 2 glass test tubes, 1 syringe and 1 comparator block for the fine range
Manufacturer's values (instructions and colour charts for the three ranges, safety data sheets).
Manufacturer and product safety
- Manufacturer
- JBL GmbH & Co. KG
- Postal address
- Dieselstraße 3, 67141 Neuhofen, Allemagne
- Contact
- info@jbl.de
- Website
- www.jbl.de
Information provided under Regulation (EU) 2023/988 on general product safety.
Wide range or narrow range?
All three versions measure the same parameter. What sets them apart is the range covered and the fineness of the reading.
| Bottom of the range (pH) | Top of the range (pH) | Use | Target waters | Tests per kit (tests) | Comparator block | Glass test tubes | Price | |
|---|---|---|---|---|---|---|---|---|
| pH 3.0 to 10.0Your choice | 3 pH | 10 pH | Screening an unknown water | All waters | 50 tests | No | 0 | 1,200.00 RSD |
| Recommended pH 6.0 to 7.6Your choice | 6 pH | 7,6 pH | Fine adjustment below 7.6 | Freshwater, aquaponics | 80 tests | Yes | 2 | 1,400.00 RSD |
| pH 7.4 to 9.0Your choice | 7,4 pH | 9 pH | Fine adjustment above 7.4 | Pond, hard water, seawater | 80 tests | Yes | 2 | 1,500.00 RSD |
Ranges, number of measurements and equipment taken from the instructions of the three versions.
Buying guide
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Parcel of 0.13 to 0.15 kg depending on the version, dispatched within 48 hours by Colissimo or Chronopost home delivery, as you choose at checkout. The reagent is sent in its original box, with a child-resistant cap. The exact cost is shown in your basket. Once unsealed, this product cannot be returned under the right of withdrawal (article L221-28, 5° of the French Consumer Code), for reasons of hygiene and health protection.
Frequently asked questions
6 questions
6 key questions
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