How to Mix Hydroponic Solution to Get a Desired NPK

If you want to grow fresh produce hydroponically, but without a smart garden that takes cartridges or pods and does everything automatically, you first need to learn how to mix hydroponic solution to get the desired NPK.

Once you understand the basic importance of hydroponic solutions, for virtually anything grown hydroponically, you have the key to successful home hydroponics.

What is a hydroponic solution, and how do you mix it? The hydroponic solution is a combination of various ingredients (some dissolvable, some liquid) that are mixed together (into the water reservoir of hydroponic growing systems) to create the desired NPK to support specific types of crops. A well-balanced hydroponic solution also promotes stable pH and EC levels within the growing system.

In no-soil gardening techniques like hydroponics, aquaponics, and aeroponics, a proper hydroponic solution replaces all of the nutrients and trace elements that plants would otherwise absorb through the soil, compost, mulch, insect droppings, and other various beneficial organic matter (like banana peels, fish, egg shells and coffee grounds).

Even more, the best NPK, as well as pH and EC level, for each type of crop grown hydroponically may vary widely.

That’s why learning how to mix hydroponic solutions to get specific results for each type of plant you want to grow hydroponically is absolutely necessary if you plan on being successful at it.

1. Change the Water in Your Hydroponic Reservoir

The first step to mixing a proper hydroponic solution for any hydroponic growing system is emptying the reservoir (or setting it up if it’s new or DIY) of all liquids.

Before refilling the tank with fresh water, clean the reservoir and rinse it thoroughly.

It is crucial to make sure that your growing system’s water reservoir is free of dirt, debris, germs, bacteria, mold, disease, and most of all algae.

Hydroponic solutions mixed in reservoirs that are poorly maintained, and teeming with algae, germs, and bacteria, will not remain stable.

So, unless you really just want to mix a new solution every few days, and flush more than dirty water down the drain (like the money it costs to keep replacing liquid nutrients, pH balancers, and more), do not skip the drain, scrub, and rinse step before filling the hydroponic reservoir back up with clean water.

2. Stir in Base Ingredients (Including Silica)

The second step to mixing up the desired NPK solution for your hydroponic growing system, and one of the most crucial ones, are stirring in your base ingredients like hydroponic fertilizer (also known as liquid nutrients) and extras like silica (if desired).

Keep in mind that each crop has its own recommended NPK for a proper hydroponic solution, as well as pH and EC levels.

That means, mixing a hydroponic solution won’t be the same exact process every time (or will at the very least utilize a range of various ingredients).

3. Dissolve Additional Ingredients (Including Cal-Mag)

The third step to properly mixing hydroponic solution, and reaching the correct NPK, is adding in the remaining ingredients.

Sometimes these final ingredients, like Cal-Mag, are granules, or powder, other times they’re liquid.

If you are using an all-purpose hydroponic liquid nutrients product, you may skip step three and move on to step four.

4. Top Off Water Levels (fill the reservoir to the max)

The fourth step of mixing solution for hydroponic systems is topping off the water levels to the maximum.

Most reservoirs have a fill line somewhere on the inside of the tank.

After you have successfully added all of your primary and secondary ingredients into the reservoir, you see exactly how much more water needs introduced into the system.

Carefully top off the water tank until the reservoir is as full as it needs to be to function properly.

5. Add-In Stabilizers (Including pH adjusters)

A fifth and final step, aside from measuring the solution when you are finished (which is explained in the next step) is stabilizing the solution.

Stabilizing the hydroponic solution is best done with test trips and a pH adjuster (small containers or powerful adjusting agents that raise or lower the pH and EC levels of the hydroponic water).

6. Take a Reading (and adjust as needed)

The sixth step to mixing your desired hydroponic solution, and getting the exact NPK you want, could technically be considered the final leg of the previous step.

However, we’ll separate the task into its own category, because it involves a digital test meter. Testing with pH, EC, and PPM, is also useful.

Stick the meter’s naked metal probe into the solution and wait a few seconds for the LED display on the meter to show you the results.

If your meter shows the desired NPK, you are finished… but, if not, you have some additional ingredients to mix in very carefully in order to reach the NPK you need.

A Final Word About Mixing Hydroponic Solution for a Desired NPK

Now that you know how to mix a hydroponic solution and get any desired NPK, or pH and EC levels for that matter, you’re ready to decide whether you should invest in a hydroponic kit with a pre-built growing system or build a DIY hydroponic system (such as a classic DIY DWC system, or a slight fancier DIY ebb-and-flow system).

Always remember to research the proper NPK, pH, and EC ranges for each type of crop you want to grow before you introduce them to your hydroponic growing system (especially if they are DIY hydroponics).

Hopefully, we’ve answered all your questions about mixing hydroponic solutions and getting the NPK you want.

But, if you have a question we failed to address please feel free to drop us a line in the comments section below! Thanks for reading.

Suggested Reading: How to Choose the Right Fertilizer for Hydroponics