There pros and cons to everything, and it’s no different when you decide to make your own hydroponic nutrient solution. For some, this seems a smart way to keep the cost of the indoor garden to the bare minimum. After all, the price of pre-mixed nutes at garden shops includes costs that have nothing to do with the quality of what’s in the bottle. For others, it might be the key to making certain crop traits more outstanding than others, a concept that hopefully follows some growing experience. And then there’s being able to become totally self-sustainable if you decide to go off-grid and live off the land somewhere in BFE.

New gardeners may not realize that a single bottle nutrient formula is very different from a two-part or three-part nutrient. Why all the fuss? It’s not just some tricky way to get you to part with more money, or make hydroponic gardening more complex.  Multiple part nutrients give the grower far more control over plant and fruit growth, and ultimately harvest quality.  The easy-to-use one bottle nutrients are general purpose, and will give you decent results from many different crops. While a one-part vegetative nutrient followed by a one-part flowering-to-fruiting nutrient will grow you a tomato plant that provides a harvest, you won’t get that good old garden tomato flavor from the crop – because that requires fine tuning the inputs you’ve used.

But we all have to start somewhere 😉 At least those one-bottle wonder tomatoes you grew will be vine-ripened while still connected to the whole plant.

Nutrient Quality

You’ll only get out of your homemade hydroponic nutrient mix what you put into it. This means you want top quality elemental salts. Purity in is a must if you’re going to have a great grow. The other super important thing is accuracy of measurement. It’s not a teaspoon of this and a cup of that. The salts are measured by weight, and an inexpensive food scale designed for kitchen use is not accurate. Find one designed for lab use. Never use improperly stored salts either. Any moisture they’ve absorbed will change their weights, which will affect your nutrient solution quality. They must be kept cool, and dry at all times.

Hydroponic Nutrient Formulas

These are basic, general purpose nutes – so if your goal is to tweak them, you’re on your own. They give you a good starting point no matter why you want to know how to do this, and have proven successful with many different hydroponic crops. The amounts in these formulas are for 1-gallon of stock nutrient solution. If you want a bigger batch, you’ll need to multiply and/or divide the measurements per gallon appropriately.

VEGETATIVE NUTRIENT

(Analysis: 9.5-5.67-11.3)

  • 6.00 gr  Calcium Nitrate – Ca(NO3)2
  • 2.09 gr  Potassium Nitrate – KNO3
  • 0.46 gr  Sulfate of Potash – K2SO4
  • 1.39 gr  Monopotassium Phophate – KH2PO4
  • 2.42 gr  Magnesium Sulfate – MgSO4 * 7H2O
  • 0.40 gr  7% Fe Chelated Trace Elements – recipe below

FLOWERING NUTRIENT

(Analysis: 5.5-7.97-18.4)

  • 4.10 gr  Calcium Nitrate – Ca(NO3)2
  • 2.80 gr  Potassium Nitrate – KNO3
  • 0.46 gr  Sulfate of Potash – K2SO4
  • 1.39 gr  Monopotassium Phophate – KH2PO4
  • 2.40 gr  Magnesium Sulfate – MgSO4 * 7H2O
  • 0.40 gr  7% Fe Chelated Trace Elements – recipe below

FRUITING NUTRIENT

(Analysis: 8.2-5.9-13.6)

  • 8.00 gr  Calcium Nitrate – Ca(NO3)2
  • 2.80 gr  Potassium Nitrate – KNO3
  • 1.70 gr  Sulfate of Potash – K2SO4
  • 1.39 gr Monopotassium Phophate – KH2PO4
  • 2.40 gr  Magnesium Sulfate – MgSO4 * 7H2O
  • 0.40 gr  7% Fe Chelated Trace Elements – recipe below

CHELATED TRACE ELEMENT MIX

  • 7.00%  Iron – Fe
  • 2.00%  Manganese – Mn
  • 0.40%  Zinc – Zn
  • 0.10% Copper – Cu
  • 1.30% Boron – B
  • 0.06%  Molybdenum – Mo

Mixing Your Nutrient Solution

Start with an clean, empty container large enough to hold your full batch. Fill it with warm water. Test the TDS/PPM and pH before proceeding. The pH will change after you’ve mixed in the elemental salts… so don’t adjust it just yet. Make a note of both meter readings. You have to take the dissolved solids content of your water into consideration, because you need to subtract it from the final reading to find the true concentration of nutrients in your solution.

Now add your precisely weighed out elemental salts ONE AT A TIME, and allow it to dissolve completely before moving on. This is not a concentrated formula. At this point you are diluting it to the strength needed to go into your nutrient reservoir. Do not add it to your system until it has totally cooled. Let it sit for an hour or two before taking the next meter readings.

You may need to adjust the nutrient concentration and/or the pH before it’s right for your plants. Hopefully, you already know the EC or TDS/PPM, and the pH level your crop requires. If not, stop and research that, because if the pH is off, the plants will have a hard time accessing what they need to thrive. Even a simple, inexpensive liquid pH test and control kit will allow you to easily measure and maintain the pH level of your nutrient solution.

A big thanks to Keith Roberto for allowing us to share his hydroponic nutrient formulas with our readers.

Callie

Callie

Contributing Writer at Garden Culture Magazine
Only strangers knock on the door at Callie's house. People who know her don't bother if the sun is shining - they know to look in the garden.
Callie