Nutrient solutions range from straightforward single part feedings to complicated cocktails with recipes that rival those of arcane potion making.
Here are 7 tips and helpful bits on nutrient mixology:
1. Start with a plan.
Most manufacturers give recommendations for use of their bottles, and some offer more detailed recommendations at their websites.¹ Read ingredients carefully and understand why you are adding something before you add it.
2. Concentrated liquid nutrients should be shaken before use.
Organic nutrients, in particular, should be well mixed as sometimes they rely on being part of a suspension rather than being a true solution.
Mixing the concentrate helps ensure that the starting ingredients are consistent and behave as expected.
Squeeze bottles can be helpful when measuring small amounts.
3. Try squeeze bottles for easy pouring.
If the original nutrient container is too large for easy daily use, consider (after mixing thoroughly) transferring a more manageable amount to a smaller container. Clearly labeled condiment squeeze bottles can make measuring shot glass measuring cup sized amounts more manageable than pouring from a large jug.²
4. Baking spoons for dry ingredients.
Since dry ingredients are frequently used in fairly small quantities, a set of measuring spoons intended for cooking can come in handy.³
5. Why are salts frequently used in nutrient solutions?
Salts are frequently used because of their ability to dissolve using water as a solvent. Water (H20) molecules are considered to be “polar” as there is a positive charge on the side with the two hydrogens (H) atoms and a negative charge on the oxygen (O) side. Salts such as potassium nitrate (KNO3) also have a positive and negative portion, in this case, K+ and NO3-. When salts come in contact with water, the negative sides of the water molecules attract the positive side of the salt, and the positive side of water molecules attract the negative side of the salt. These forces break apart the salt, dissolving it in the case of potassium nitrate into potassium and nitrate, which are available to the plant as nutrients.4
Measuring spoons can be used for small amounts.
6. Nutrient lines often have two or more parts.
Part of the reason that two (or more) part recipes are common is that there are certain common ingredients that if combined full strength will bond to each other stronger than the water’s ability to tear them apart. After combining they will precipitate out of solution (sink to the bottom) and be unavailable. Each part of a recipe should be added to the nutrient solution individually to allow dilution before the next ingredient is added.
7. EC meters estimate an overall nutrient level.
Pure water does not conduct electricity, but once conductive materials such as salts are introduced, the nutrient solution will. Electrical Conductivity (EC, ppm) meters are best at estimating the nutrient levels when salt based fertilizers are used since salts have a large impact on conductivity.
Footnotes
- Specialized week to week schedules are available for many nutrient lines.
- Squeeze bottles with a measuring shot glass is my favorite combination for personal scale gardens.
- Just make sure not to confuse them with the regular cooking measuring spoons kept in the kitchen.
- If the salt leaves an unused residue, this can result in “salt buildup”, and is treated by watering with clear water (flushing).