How to Mix Your Own Fertilizer Blends

MisterBlah

Well-Known Member
This is a short tutorial on the physical steps it takes to mix your own nutrient stock solutions. It's awfully simple, sure, but I figured it's worth posting. I know many of you that might be on the fence will realize it's just as easy as baking or cooking.

So now you've decided you want to save a lot of money on your fertilizer blends and mix them yourself. But maybe you don't know where to start. This guide should lay it all out for you, just like a recipe for baking cookies.

First, you need to know what blend you want to make, what recipe to use. You can find a bunch of recipes in my Fertilizer Database.

Then you need your ingredients. You need to buy some fertilizers. There's a lot of places to buy them. Do a good search for each of the items on the list. Or visit websites like cropking.com, plantsthatproduce.com, Amazon, or even eBay. There are plenty that sell the fertilizers we will be using. If you're worried about what you're buying, feel free to contact me or leave a comment here. I'm happy to help.

You will also need a few tools to complete the job. You should be able to acquire everything you see here for under $75.
  • A balance with 0.1g precision, 0-300g range at a minimum.
  • A balance with 0.001g precision, 0-20g range at a minimum.
  • A graduated cylinder, 500mL minimum. Plastic is okay.
  • Two bottles for storing the mixture, you probably already have one.
Search Amazon, eBay, or any other part of the Internet to find these.

The last thing you'll need is some distilled water. Your local grocery store should sell some. Specifically distilled water though. Anything labeled "drinking water" or "spring water" will have minerals and nutrients in it that will through off the blend you are about to make. If you have an RO filtration system, water from that will work as well.

Now that you have everything, you need to create the stock solution. We are going to create a 1.0L stock solution. We are going to use a CalMag Blend with micro-nutrients as an example.

This recipe for a 1.0L stock solution uses the following:
  • Calcium Nitrate: 170.0g
  • Magnesium Nitrate: 117.7g
  • Fe-chelated 18%: 5.000g
  • Mn-chelated 18%: 2.777g
  • Zn-chelated 20%: 2.500g
Step 1: Measure out 500mL of distilled water with the graduated cylinder and pour it into a bottle ~1.0L in volume. Label this bottle #1.

Step 2: Weigh out macro-nutrient fertilizers(Calcium Nitrate and Magnesium Nitrate) first using the 0-300g balance. Empty these into Bottle #1. Swirl it around, but do not shake it yet. It's okay if not everything dissolves at this stage.

Step 3: Weigh out the micro-nutrient fertilizers using the 0-20g balance and empty them into Bottle #1. Swirl the bottle some more. You might have noticed the chelated micro-nutrient fertilizers that I have in the recipe above are specifically the Biomins Glycine chelates from JHBiotech. There are many chelates you can use, so if you don't want to use those for this recipe that is okay. More on this in another article.

Step 4: Measure out another 300mL of water. Empty it into Bottle #1. Close the bottle. Shake and wait for everything to dissolve.

Step 5: Measure out 500mL in the graduated cylinder from the bottle that you have your stock solution in. Pour this into a second bottle. Label this bottle #2.

Step 6: Empty the remainder of Bottle #1 into the graduated cylinder and fill it up to 500mL with distilled water. Pour into Bottle #2. Bottle #2 now has your completed fertilizer stock solution.

Congratulations! You've just mixed your own liquid fertilizer blend! Now use it just like you normally would.
 
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churchhaze

Well-Known Member
I like this guide, but I do have one problem with it. You're adding 1L of water with the salts rather than ending up with 1L stocks.

1ppm means 1mg/L where L is liters of the solution, not the amount of water.

To get 1ppm of X, the combination of water + 1mg of X must be 1L.

Sorry if this is already included in your calculations.
 

MisterBlah

Well-Known Member
I like this guide, but I do have one problem with it. You're adding 1L of water with the salts rather than ending up with 1L stocks.

1ppm means 1mg/L where L is liters of the solution, not the amount of water.

To get 1ppm of X, the combination of water + 1mg of X must be 1L.

Sorry if this is already included in your calculations.
You are 100% correct here. Sometimes I should reconsult my chemistry books instead of insisting I remember everything all the time.

I've fixed things to account for this.
 
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