Nutrient Lock-out

Nutrient Lock-out Information

Most seasoned growers have experienced the moment when you realise that your plants aren't looking too good and they haven't really grown in the last few days. Below is a little check-list of things to help ensure that what is commonly known as lockout only lasts for the shortest amount of time possible.

Remember this though, even if you go through this check-list and it highlights a few things you are doing wrong and you do correct them, your plants won't start growing again overnight. Give them a day or two to come round from their lockout. Be patient and during this period foliar feed daily to avoid any discolouration in the leaves and stems as the plant will usually not be feeding from the roots.

The three main things to look at are:

  1. Temperatures: Are your temperatures right? The most common cause of lockout is severe temperature drop when your lights are turned off. Try to ensure it isn't getting colder than 18°C or 60°F. Have a heater come on when the lights turn off to combat this. With this in mind also check it's not getting too hot when the lights are on as temperatures above 30°C or 90°F can also be a cause for lockout through excessive transpiration.
  2. Over watering: By over watering I don't mean overfeeding, that can be a different issue. When I say over watering I mean in terms of the volume/amount of water you give your plant at any one time. By giving your plants excessive amounts of water you will suffocate the roots and cause the plant to lockout as it can no longer feed until the growing medium dries out. If you have overfed small plants try placing them on a heat mat - this will speed up the drying out of the medium.
  3. Overfeeding: Overfeeding is a common mistake as many growers are misinformed that the more nutrient they feed the plant the faster/bigger it will grow. Excessive amounts of any nutrient can cause lockout. When the nutrient is too strong the tips of the roots that take the water is up the plant are burned by the excessively high strength nutrient, the plant becomes unable to feed and goes into a state of shock or survival mode where it only takes just enough food to survive. If this happens you will notice that suddenly your medium is not drying out at the rate that it previously was.

Flushing your medium should be considered. To reset your medium back to how it came out of the bag you will need to pour plain water with a pH 5.5-6.0 through at a rate of 3 x the volume of the pot. For example, a 10 litres pot would require 30 litres of water. This is generally only in extreme circumstances, depending on how much you overfed your plants will determine how much water you need to flush your plants.

To check if you have flushed enough you need to measure the run off.

These are the three main causes of plants not growing (lockout). If you have checked all these and you are still not seeing any new growth after a few days, please don't hesitate to get in touch with us here at SpaceHydro - our experienced staff will be happy to go through everything with you to get your plants growing again.