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How to Make Water Soluble Calcium at Home

Believe it or not, calcium is as essential for plants as it is for humans. It is commonly found in nature and is second to being as common as oxygen. In the form of calcium carbonate, calcium can be extracted from something as common as eggshells when paired with vinegar. Natural and organic farmers, even gardeners, tend to create their own water soluble calcium at home. This is because all of the ingredients required are those you can find in most households, especially if you love eggs. So, how do you make water soluble calcium?

What’s the best recipe?

Not all water soluble calcium techniques are the same, but they all have a universal idea with similar ingredients. Our recipe generally includes eggshells (as many as you can find) and vinegar. Eggshells carry lots of calcium carbonate, but it is trapped within the eggshell and needs to be extracted. Vinegar is useful for this since it separates the calcium from the eggshell while producing carbon dioxide.

As for the best recipe, that’s up to you! We like to keep it pretty simple when making the solution, as we explain below. Of course, there are other options out there, so feel free to test away or even make your own recipe!

But, why even make water soluble calcium?

Water soluble calcium is ideal for farmers and gardeners who wish to give their plants and crops a quick calcium boost. It prevents crops and certain plants from overgrowing, increases the longevity and hardness of fruits, provides plants and crops with proper nutrition and encourages plant-life to absorb nutrients much easier.

Ingredients Needed:

How do you make water soluble calcium?

  1. Gather your eggshells and clean them out. Be sure to remove any sticky layer within the underside of the eggshells. This will ensure the eggshells solely contain the calcium we wish to extract and nothing else.
  2. Using your crushing tool, or your palm, carefully crush the eggshells into small pieces. Avoid crushing the eggshells into a powder form. Crushed eggshells will allow the process to be quicker and much more effective.
  3. *Optional: Roast the shells over a fire to remove any substances that could possible rot during the process of making water soluble calcium. Be sure to avoid browning or burning the eggshells. (We usually roast ours)
  4. Fill your mason jar or polyethylene container with your vinegar and add in the eggshells. The eggshells will move within the jar or container and will produce bubbles while they melt into a liquid.
  5. Your solution is done when there is no longer any movement or bubbles being produced.


  • Once you rinse or clean out your eggshells, allow them to dry.
  • Slowly place your eggshells into the vinegar solution, little by little.
  • The lack of bubbles means the eggshells and spaces in between them are saturated with vinegar.
  • For any eggshells that sink to the bottom, remove the water soluble calcium solution and add in more vinegar to make more solution out of the leftover eggshells. This happens when there are too many eggshells in the vinegar, making it hard to melt.
  • Know that your home/kitchen will smell of vinegar and eggs, so open some windows and turn on a fan or two because it’s about to get stinky!
  • Store your solution in a cool, shady area at room temperate. Be sure there is no contact with sunlight in your storage area. We generally put it in a kitchen cupboard that is rarely opened and all the way in the back.

How do you use water soluble calcium?

Water soluble calcium can be used widely across your garden and farm. You can use your solution for a variety of things, including when:
  • plants or crops overgrow
  • plants or crops aren’t growing correctly
  • leaves are discolored
  • flower buds are discolored
  • fruits are too soft
  • plant nutrition is low
  • flower blossoms begin to fall
  • you want to increase the flavor of vegetables and/or fruit

Your water soluble calcium solution should be diluted prior to applying to your plant’s or crop’s soil. The dilution ratio is typically 1 part calcium solution to a 1000 parts non-chlorinated water. However, depending on the strength of your batch, you may find you need more or less than that by a little. To figure this out, you can do one spray and wait a few days to see where the health of your plants are at. If there isn’t much change, you may decide to lean more towards a 1:500 ratio instead.

It’s all a balancing act and once you get your recipe down, you’ll know the exact amount needed in no time. After just two or three batches, we figured out the ratio we needed to keep when feeding this to our plants. Generally, the only time we use it is if the plants are showing a calcium deficiency, but it can be used at any time if you wish.