Indoor hydroponic gardening involves careful management of complex biological systems. When you garden indoors, you are essentially taking over the roll of mother nature. You provide the sun, the food, and the air that your plants need to flourish. The idea is to optimize each of these systems so that you are doing a better job than nature can. This involves a delicate balancing act that can be difficult to maintain at times. When things start to go wrong, it can be difficult for a beginner to diagnose the exact cause and decide on a course of action.
There are many sources online that are at your disposal when searching for answers but the sheer amount of information can be overwhelming unless you are able to search for the exact problem. It also helps to establish a relationship with your local hydroponic or organic gardening store. They are experts and enjoy sharing their knowledge with those interested in the hobby.
Whether you are searching online or asking a local expert, there are some general questions that you will be asked:
- What is happening in your garden?
- When did the problem first occur?
- What size is your grow room?
- How many lights and what type are they?
- What type of hydroponic system are you using?
- What type of grow medium is being used?
- What is the day and night time temperature?
- What is the temperature of your nutrient solution?
- What is the pH of the nutrient solution and the medium?
- What is the strength of the nutrient
and what type? - What stage of growth are the plants in?
- Did the problem start on one plant and spread or where all plants affected at the same time?
- What do the leaves look like?
- Are only certain areas of the plant effected?
- Have you seen any bugs on the bottom or top of leaves or in the medium?
- Have you done anything different?
Have you sprayed the plants with anything recently?
Knowing the answers to these questions will make your search for answers much easier. Who knows, you may even figure out the problem yourself.
To understand the mechanics of nutrient lockout and how to prevent it from occurring, you must first have a basic understanding of how plants take in nutrients. (WARNING! Science content!) Most of a plants sustenance is taken in through the roots through a process called osmosis. Osmosis is the physical process by which a solution of low concentration translocates through a semi-permeable membrane to a solution of higher concentration on the other side of the membrane. This process is what allows roots to absorb water from the surrounding soil. As osmosis occurs, energy is released and used to fuel plant growth. Now enter nutrient lockout.
The passage of water and nutrients through the root membrane is controlled by the relative concentrations of individual nutrient elements on either side of the membrane. If the concentration is higher in your grow medium than in the roots, then the plant can dehydrate by releasing water and nutrients from inside of the roots to the grow medium.
So, in laymans terms, if you have a very high concentration of nutrients going to your grow medium then you can seriously mess up the plants biological processes. For hydroponic hobbyist, this usually occurs because of an adjustment to the nutrient solution in the reservoir to compensate for a nutrient deficiency. Since nutrient lockout has the same symptoms as nutrient deficiency, it is often hard to diagnose and recover from.
The passage of water through the semi-permeable membrane is controlled by either the TDS (total dissolved solids) or EC (electrical conductivity) of the nutrient solution. So, if the EC of the solution you’re feeding is excessively higher than the EC currently in the roots, the plant can dehydrate by drawing water out of the roots and into the medium via osmosis.
The best defense against nutrient lockout is to routinely monitor your nutrient solution at the reservoir topping off as needed and flushing every two weeks.