Water analysis
Water analysis is carried out on different types of water, drinking water, groundwater, surface water and waste water. For horticulturists and farmers, it can be raw water or ready-made nutrient solutions.
A water analysis is an examination of the water sample to find out its chemical and physical properties. This is done to investigate whether the water is suitable for drinking, to check that it meets statutory limit values for various parameters, or to investigate how the water is affected by various factors such as wastewater or algae blooms. A water analysis can include measurements of parameters such as pH, alkalinity, plant nutrients, chemical oxygen consumption (COD-Mn), chloride and many others.
Scope of the water analysis
Our water analysis includes pH, conductivity, nitrate nitrogen, ammonium nitrogen, phosphorus, potassium, magnesium, sulphur, calcium, manganese, boron, copper, iron, zinc, molybdenum, silicon, sodium, aluminum and from 01/03/2024 chloride is again included in the analysis.
Water analysis for growers
Take water samples on raw water for irrigation or on ready-made nutrient solutions.
Raw water for nutrient irrigation
Water analysis is carried out with additions for alkalinity (bicarbonate content, the water's buffering capacity) in order to be able to calculate how the pH should be adjusted in the fertilizer recipe (see more information further down the page).
Odling with drip irrigation in the open field
Take a sample of the nutrient solution as a check that the correct nutrient composition is in the solution. Complete with spurway analysis on Earth.
Odling in substrate
Take samples both in the outgoing nutrient solution and from the water that is drained off from the substrate (drainage water), or press water from the substrate. Sampling in substrate cultivation with nutrient solution is repeated every two weeks for continuous adjustment of the fertilization.
Especially at circulation of nutrient water water analysis is an important tool for continuously adjusting fertilization. In this way, the grower can optimize the nutrient composition and control the irrigation to avoid the accumulation of substances that the plant does not consume much of. That precision fertilization gives a better result in terms of production, quality and the environment. With the right added nutrition, the result will also be better on the last line!
Drinking water from own well
Analyze drinking water to see if it is serviceable. If it contains elevated levels of certain plant nutrients, it is a sign of organic pollution from sewage or from animal husbandry. But if the levels of plant nutrients are below the Norwegian Food Authority's limit values, then the water is of good quality and further analyzes should not be necessary. If the water is to be drunk by children under the age of 7, fluoride should also be analyzed in addition to our standard analysis.
To find out what the different limit values for drinking water from your own well mean, see the attached link on the Swedish Food Agency's website:
Optional Alkalinity
If the water is raw water to be used as a nutrient solution, request additional analysis of alkalinity. Alkalinity is the water's buffering capacity or hydrogen carbonate ion content, (HCO3-).
At alkalinity above 100 mg/l, acid needs to be added to turn the carbonates into carbon dioxide, so that the alkalinity is adjusted down to 50 mg/l. More than that must not be removed, because then the pH value becomes unstable and can become far too low.
Example: If the water has an alkalinity of 280 mg/l, then you want to neutralize 280-50=230 mg/l. Then multiply the amount of acid to be added according to the table below by 230/100. If 62% nitric acid is to be used, then it becomes 0,12 x 230/100 = 0,276 liters of nitric acid per 1000 l of irrigation water. Read more…
To neutralize 100 mg/l of HCO3- per 1000 liters of irrigation water, the following amount of acid is required:
| Acid product | per 1000 l of irrigation water | per 100 l stock solution with 1:100 tension |
|---|---|---|
| Phosphoric acid 85% | 0,10 liter | 1,0 liter |
| Phosphoric acid 75% | 0,125 liter | 1,25 liter |
| Magnofoss | 0,17 liter | 1,7 liter |
| Nitric acid 62% | 0,12 liter | 1,2 liter |
| Nitric acid 53% | 0,145 liter | 1,45 liter |
Other water analyses
Sampling instructions water analysis
LMI provides 250 ml sampling bottles for the purpose.
The sample must be representative of the water to be analyzed. Fill the bottle all the way up, so that there is no air left. In the case of multiple samples, label the samples with sample numbers. Attach delivery note as below. If the sample is not delivered to the laboratory immediately, it should be stored in a refrigerator.
Submission of samples
Certain analyzes must be performed within a short period of time:
- COD-Mn and suspended matter should be analyzed within 24 hours.
- pH, nitrate and ammonium should be analyzed as soon as possible.
- Phosphate-phosphorus must be submitted immediately to be filtered within 4 hours.
- Bacterial analysis must be passed on to another laboratory on the same day the sample was taken. Submission no later than 13.30:XNUMX p.m. on weekdays (except the day before Red Day, when we do not accept bacteria samples). We do not accept samples for bacterial analysis by post.
By send in samples it is approved that analysis is carried out even if delivery to the laboratory took more than a day.
Delivery note
Attach delivery note with sample number/sample name. Remember to state the name and invoicing information (including organization number/social security number), as well as e-mail address of the people to whom we will send the results. For packing slips…
Response time
Analysis responses to mineral analysis of drinking water and nutrient solutions are submitted on e-post day after that the sample reached the LMI, or the same day if the samples are submitted no later than 09.30.
Other analyzes take about 10 working days.
