Posts Tagged ‘lab testing’

So you sent us a water sample… what happens next???

First the JRP Lab checks out the alkalinity.  The higher the alkalinity, the more acid it will take to bring your water into working range for your crops.  The smaller your container size, the more problematic the high alkalinity is.

When we see high alkalinity water it may cause a gradual increase in the growing media pH. Often times it may be necessary to inject mineral acid (sulfuric or phosphoric) into the water or to use acidic media amendments, such as sulfur, or “acid-forming” fertilizers.

** Helpful hint: Do not use water that has been water softened. Water softeners add harmful sodium while removing desirable calcium and magnesium. Water softeners do not reduce water alkalinity.

On the other hand, low alkalinity water usually lacks the components that neutralize acid. As a result, the continued use of potentially acidic fertilizers may result in pH crash in the medium.  In addition, these waters are often deficient in calcium, magnesium or sulfate and additional supplements may be needed.

Next up we check the nutrients that may cause a concern. Elements such as sodium and chloride can cause plant toxicity at high levels.

Finally, let’s find your perfect match!  Call the Jack’s technical team for personalized recommendations based on your crop and water!

From more information take a look at these in-depth articles: KNOWLEDGE CENTER

If you haven’t yet sent us a water sample and want to learn how to take a water sample, check out our “how to” video: HOW TO TAKE A WATER/FERTILIZER SAMPLE


Water Quality and Choosing the Right Fertilizer

Choosing the right water JR PetersKnowing your water quality is the first step in successful growing. There are many different factors that come into play. No two water sources are exactly the same, so in theory what works for the grower down the road may not work for you.

Water alkalinity plays the biggest role in choosing the correct fertilizer. A simple way to think of alkalinity is as the ability of your water to neutralize acid. The higher the alkalinity, the more acid it will take to lower the pH of your water. Plus, water alkalinity is often an indicator of your pH and Ca levels in your water. Low alkalinity or pure water sources (less than 60ppm alkalinity) are often lower in pH and lacking in secondary nutrients like calcium and magnesium. I usually recommend picking a basic or neutral fertilizer with added calcium and magnesium, like Jack’s 17-4-17 pure water or Jack’s 15-5-15 cal-mag. Occasionally, you may need a booster of a higher acidity fertilizer like Jack’s Petunia FeED or High Performance, so make sure you have some on hand. Low alkalinity waters are classified as waters with less than 100 ppm of alkalinity.

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Testing at the JR Peters Laboratory

Here at the lab we have tested over 1 million samples for growers and researchers. We test these samples so we can stop problems before they start and help fix them if a situation arises. Testing should also be done if you are having a great crop, then you can repeat the program in the future.

The most important test is a water test. Knowing your water quality is the key to success. Water quality can effect fertilizer selection, MOST usage, nutrient uptake by the plant, and nutrient toxicities. We recommend having your water tested every year in December or January before starting up for the spring.

Water Analysis Parameters:
pH, Soluble Salts, Total Alkalinity, Total Nitrogen, Nitrate Nitrogen, Ammonium Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulfur, Iron, Manganese, Copper, Boron, Zinc, Molybdenum, Aluminum, Sodium, Chlorides

Most growers will also send in an unused media sample to test before planting. By doing this you will have a good baseline on your media in case problems arise over the growing season. It will also be able to tell you if any additional media amendments will need to be made. Media tests are also handy to have in case you are experiencing a crop issue. Is the pH off, nutrient levels out of balance, or are salts accumulating? A media test will give you all this and more.

Standard Media Parameters:
pH, Soluble Salts, Nitrate Nitrogen, Ammonium Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulfur, Iron, Manganese, Copper, Boron, Zinc, Molybdenum, Aluminum, Sodium, Chlorides.

Tissue tests give you a snapshot of the tissue at the time the sample was taken. They also reflect the conditions of the media 2 weeks prior. The key to tissue samples are correct sample procedures. Take care to rinse off any fertilizer, chemical or media residues, as these can skew the results. The most recently matured leaves should be sampled. If sampling for a problem make sure you take affected leaves off at the same location on plants. You should also be sending in a healthy plant tissue sample as well. I usually recommend sending in a media sample for problem plants as well. By sending in both media and tissue you get the most accurate reading, and will help for a better diagnosis.

Tissue Parameters:
Total Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Iron, Manganese, Copper, Boron, Zinc, Molybdenum, Aluminum, Sodium

For more information or to get testing supplies call 1-866-522-5752 x46 or email us at