From
NebulaHaze thee authority:
Get Nutrients That Let You Mix Water Ahead of Time
When you need to make nutrient water for your cannabis plants, it can take several minutes to make up a new batch every time you water.
Instead, as mentioned earlier you can make a lot at once and only use it as needed.
But how long can you store pre-mixed nutrient water?
- Nearly all nutrients can last at least 1 week after being mixed with water without any negative effects on your plants
- For nutrients comprised solely of inorganic ingredients, your pre-mixed nutrient water can last for 2-3+ weeks without a problem even if the nutrient water is just sitting in the container.
How do you know which is which? Look at the label of your nutrients where it says “Derived fromâ€
All the ingredients in the above picture are inorganic minerals and “chemical salts.†They all have "molecular" sounding names. When it comes to hydroponic nutrients, you will almost always see these types of ingredients specifically because they will not cause reactions or problems even when sitting in water for long periods of time.
But it’s not just hydro! Lots of soil and coco coir nutrients also use the same sources of nutrients because these specially derived mineral sources don’t need to be broken down and are available to your plant immediately.
As long as you don’t see any organic ingredients on the label, you know your nutrient water can be premixed for 2-3+ weeks. If you do spot organic ingredients on the label (like “seaweed extract†in this next example) then you probably shouldn’t let your nutrient water sit as long because organic material tends to start up biological processes. Ultimately this could cause things to grow in your water, possibly altering the nutrient content or even introducing some nasty microorganisms to your plant roots.
If you see any organic ingredients listed, like “seaweed extract,†don’t let your mixed nutrient water sit for longer than a week.