How to Use Pre-Empt

PRE- EMPT: An organic hydroponic fertilizer

Pre- Empt is a OMRI-listed product that can completely replace conventional hydroponic fertilizer programs. Pre-Empt is used in recirculating hydroponic systems growing crops such as lettuce, leafy greens, basil and other herbs. This fertilizer is created through five stages of fermentation processes that incorporate molasses with other natural plant extracts. This process packs Pre-Empt with essential macro- and micro-nutrients, amino acids like humic and fulvic acid, as well as an array of vitamins which build a full spectrum of nutrients.

Our research has shown that Pre-Empt does not need to have any pH adjusters added to the product in order for the plants to receive optimum nutrient absorption. However, some well water can vary in alkalinity and, at times, may require pH adjustment. If needed, citric acid is an OMRI approved product that may be beneficial. We do not recommend using the same pH management strategies used with traditional fertilizers. Small swings in pH should be expected. PreEmpt organic hydroponic nutrients can also be used in conjunction with other products including other fertilizers (such as a solution grade organic gypsum (calcium sulfate) and magnesium sulfate), insecticides and fungicides.

Benefits

  • OMRI listed complete organic nutrient package
  • Derived from all natural plant extracts
  • Improves Ion exchange between plants and water
  • PreEmpt comes in a concentrate that requires little agitation when mixed with water
  • Can be used with supplemental fertilizers, insecticides, and fungicides
  • Around a pH of 4, which reduces amount of pH Down required
  • Can completely replace conventional nutrient programs for leafy greens
  • Has been shown to have similar production cycles as traditional fertilizers.
  • Growers have been able to go 90 days between reservoir changes (and possibly beyond)
    – The flushing frequency will depend on the growing environment, system, water source, and fertilizer rate.In general, using a water source with a very low EC and keeping the fertilizer rate low will help extend the life of the reservoir. Some growers flush their system once every 4-5 months and some growers flush every two weeks.
  • When used properly, it won’t clog 1/4″ emitters which is very rare for an organic fertilizer.

We strongly suggest pairing Pre-Empt with Terra Bella, a root microbe inoculant, to naturally promote the uptake of nitrogen and other essential nutrients for plant growth. TerraBella’s highly concentrated blend of microbes naturally promotes uptake of nitrogen and other essential nutrients for plant health. Plants can take nitrogen only as nitrate or ammonium. Organic material tends to increase ammonia, which is not good for plants. Therefore nitrifying bacteria are necessary in order to make nutrients available for the plant. The combination of aerobic and anaerobic microbes in Terra Bella works throughout the root zone to increase crop yield and resistance to disease and pests.

How to use Pre-Empt:

As mentioned before, we recommend pairing the use of Pre-Empt with Terra Bella. In order to create the final nutrient solution for your system, the following steps should be followed:

Creating a 300 gallon nutrient solution:

  • Removing chlorine from tap water (City water): In case you are working with tap water, we recommend eliminating chlorine in order to improve source water quality. Fill your reservoir with water allowing the chlorine to dissipate. Adding aeration will speed up this process. To remove chlorine for the prepared inoculant we need to add 1 oz molasses to a 5 gallon bucket with water. After this step you should let water sit for 1 day.
  • Mixing the inoculant: For Terrabella it is recommended to add 2 oz of product per 5 gallons of chlorine free water containing the 1 oz of molasses you prepared the day before. After this step you should let the inoculant sit for 1 day before adding to the reservoir. 1 gallon of prepared inoculant can be used in 60 gallons of nutrient solution. It may also be a good idea to add in an airstone for this step.  You will add prepared TerraBella to your nutrient solution/ reservoir every two weeks for the first two months. Some growers reduce the frequency of TerraBella additions after the first two months, cutting back to once every month or month and a half.
  • Creating final nutrient recipe: For Pre-Empt it is recommended to add the product until your EC is ~1.0 above your source water EC. This will take approximately 1 oz (30mL) of Pre-Empt per gallon. For a 300 gallon nutrient solution about 300 oz (2.4 gallons) are needed.

Start a new system at a low fertilizer rate while establishing microbial population.

  • First week bring reservoir to ¼ strength by adding ~7.5 mL/gallon Pre-Empt. Add prepared TerraBella inoculant at full strength (~63 mL/ gallon of nutrient solution).
    • Second week bring reservoir to ½ strength by adding another ~7.5 mL/gallon Pre-Empt.
    • Third week add prepared TerraBella inoculant at full strength. (~63 mL/ gallon of nutrient solution). The pH should start to stabilize around this point if not using additional products for pH management.
    • After the first few weeks slowly bring up the EC to full strength by adding the final ~15 mL/gallon Pre-Empt. Some growers target an EC of 1.2-1.4 (with a source water EC of 0.3). We have not seen significant improvements in growth rate when EC is raised up from 0.9 up to 1.4, but have seen an increase in biofilm development and pH swings. We recommend keeping the EC low to keep the system stable, but if plants are showing deficiencies it may be necessary to increase fertilizer rate. When adding fertilizer it is best to spread out the additions over several days instead of giving large fertilizer doses. Large fertilizer additions can lead to intense pH swings.
  • Avoiding unwanted bacteria in your system: In order to avoid development of anaerobic bacteria we must keep our reservoir with good oxygen levels (From 7 to 30 ppm oxygen).
  • Maintenance: You must maintain your target EC (~1.0 above your source water EC). In order to maintain EC, water levels should be monitored so we can replace water evaporated and taken up by plants. Also more fertilizer (Pre-Empt) must be added regularly in order to maintain nutrient levels. A great advantage of this product is that with Pre- Empt there is no need to adjust pH. It is really easy to use! 
  • It is not recommended to utilize any antimicrobial agents/ equipment in the nutrient solution in order to maintain a healthy microbial population. (ex. H2O2, UV or ozone systems)

Crops and hydroponic systems recommended for the use of Pre-Empt

Organic hydroponics is possible! We can implement organic practices for hydroponic systems by using nutrient solutions derived from organic plant and animal material or naturally mined compounds. 

Pre-Empt is considered a complete formula to use in recirculating hydroponic production for leafy greens in NFT, DWC and Ebb and Flow systems. The use of this product for open systems may not be ideal due to operational cost.

Due to nutritional content, Pre-Empt can possibly be required to be supplemented with other nutrients such as calcium when used for vine crops such as tomatoes. Organic solution grade gypsum and silica may be used in order to increase Ca levels.  The nutrient content alone from Pre-Empt can promote vegetative growth for fruiting crops.

In order to maintain organic status, please certify the organic origin for a product before use. The Organic Materials Review Institute (OMRI) is a private, nonprofit organization that determines whether or not a product qualifies as organic under the USDA’s National Organic Program. Product certifications can be searched at OMRI.org.

For more details, please refer to Organic Hydroponic Leafy Greens.