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Hydroponic Solution Basics

If you thought hydroponics equipment was confusing, wait ’til you see the vast array of hydroponic solution choices out there! There’s bloom mix, super shot, mix for lettuce, tomato special. There are one-part, two-part, and even 3-part mixes, and dozens of brands of each. And then there’s Iguana Juice and Happy Frog and Dr. Hornby’s Big Bud. Heavens! Which one is best for your garden?

Our Beginner’s Guide To Hydroponics is on sale for a short time. Check it out!

Hydroponic solution

Let’s make this real simple… use the stuff NASA uses! Read on to find out what that hydroponic solution is…

No matter which hydroponics system you decide on, there is one factor common to them all: a nutrient solution.

This liquid fertilizer contains all the nutrients your plants need, in a readily absorbed form, delivered right to the root zone of the plant. This creates
perfect growing conditions, resulting in bumper crops of delicious, nutritious produce. It’s what hydroponics is all about!

Now, I know you don’t want to hear all the scientific formulas and chemical processes involved, but a little bit of knowledge will help you understand and troubleshoot better if things go wrong.

The hydroponics process is so dependent on proper nutrition, that we strongly encourage you to read this section. It gets into the “nut and bolts” of running a successful hydroponics project.

Hydroponic Solution Formula

Start with healthy water

A drop of water making waves

Starting with healthy water is the basis for a successful hydroponics experience.

If you’re going to be using city or well water, get it tested first to see where you stand. You can do this inexpensively through the county ag agent or health department, or through an independent lab. If using tap water, you can call the water company and ask them the calcium content of the water.

Basically, what you want to know is if you have very hard or very soft water. Hard water has lots of mineral content and calcium carbonate in particular. If you see calcium buildup (white residue) on your faucets, you probably have hard water.

Soft water has low mineral content, which is preferable. (But you cannot use water that has gone through a water softener system for hydroponics… it’s way too salty).

Okay, so you found out you have hard water (Calcium content is above 70 ppm). What can you do about it?

Simple: The GH Flora hydroponic solution we recommend later has a base solution specifically for use with hard water. Instead of using FloraMicro, simply buy Hardwater FloraMicro. Problem solved!

If you find out that you have really poor water, (greater than 300 ppm total solids), consider installing a RO (reverse osmosis) water filter under your
kitchen sink. An RO filter costs $150-$300, but it provides the highest quality drinking water possible.

If you are stuck with mineral-laden water, you must use an RO filter if you want a successful hydroponics experience (and a healthier family).

Another alternative: you could collect rainwater in a barrel and use that for your garden. Sweet!

“The garden suggests there might be a place where we can meet nature halfway.” ~Michael Pollan

Add hydroponic fertilizer

I know we promised to keep things simple, but a little bit of science is in order here. Understanding what hydroponic fertilizer solutions are made of will help you become a better urban farmer!

First, some basic information on hydroponic nutrients. Later, we give you some really neat tips and tricks to make reservoir maintenance a snap! So stay with us for the good stuff.

Micro & macro nutrients

Here’s your mini chemistry lesson for the day: in hydroponics, you take soil away from the plant, so you must supply perfectly balanced and complete nutrition for it.

Plants need large amounts of 6 macronutrients: Nitrogen (N), Phosphorus (P), and Potassium (K). The NPK numbers you see on a manure or fertilizer bag (like 30-10-30) are simply telling you at what ratio these three macro-nutrients are mixed in that bag of fertilizer. The other 3 macros are calcium, sulfur, and magnesium. All 6 are provided in the proper ratio in all hydroponics solutions.

Plants also need micro-nutrients (minute traces of other elements) in order to thrive, just like you do. The nutrient solutions you buy for your ‘ponics garden are different from ordinary plant fertilizers. They include all the trace elements, too.

So, the hydroponic solution is kinda like your one-a-day vitamins: it contains traces of iron, boron, manganese, zinc, molybdenum, copper, cobalt, chlorine, selenium and silicon. Yum!


Part 2 of your chemistry lesson (and this is important): Remember pH from chemistry or biology class? All pH is, is a number that tells how acid or alkaline your solution is. This is important because if the pH is not in the proper range, nutrients get “locked out” and the plant can’t get to them.

Luckily, pH is a very easy thing to control. All you need is a pH test kit (like for swimming pools), or pH “dip” strips. Either testing method is inexpensive and very easy to learn. You do NOT need to buy an expensive electronic pH meter, which also requires quality control procedures.

The proper range of pH for your nutrient solution: 5.5-6.5 (6.0 is ideal).

When to test:

  • When you mix up a new batch of grow juice. Let it settle for a couple of hours. Then test and adjust the pH. Let set an hour and test the pH again…
  • Twice a week thereafter. If you are a worrier, test your hydroponic solution daily. It only costs a few drops of the test solution.

How to adjust the pH:

  • Buy a “pH up & pH down” kit. Follow the directions on the bottle. A little bit goes a long way, so be careful. You’ll soon figure out how much is about right.
  • In a pinch (if you run out of the kit solution), you can fix the pH with these “home remedies”. White vinegar will lower the ph; baking soda raises it. But these agents are not stable and buffered, and should not be used in the long run.

Do yourself a favor: Get this kit put out by GH (General Hydroponics). It includes the test kit plus a bottle each of pH up & pH down. It’s inexpensive and will get you through many gardens. Piece of cake.

General Hydroponics HGC722080 pH Control Kit For A Balanced Nutrient SolutionGeneral Hydroponics HGC722080 pH Control Kit For A Balanced Nutrient SolutionGeneral Hydroponics HGC722080 pH Control Kit For A Balanced Nutrient Solution

For best results with your hydroponic solution:

  • Keep the reservoir at 60-75 degrees.
  • Keep it aerated with an airstone or bubbler.
  • Keep the pH between 5.5-6.5 (shoot for 6.0). Stay on top of the pH!  
  • Add a few drops of hydrogen peroxide to the reservoir weekly to cut down on algae and bad bacteria.

Which nutrient mix is the best?

Here’s some solid and simple advice about the hydroponic solution:

  • Only buy solution formulated specifically for hydroponics. Regular fertilizer or Hyponex will kill your garden.
  • Buy the best quality nutrients you can. It makes a difference, and a little bit goes a long way. Don’t put together a Cadillac growing unit, then try to economize by using cheap nutrients. You’ll be crying in your onions!
  • Do not buy “organic” nutrients. Organics require decomposition (composting) which creates inconsistency in the solution and your results: something you are trying to eliminate. “Organic” sounds good… but it’s not… not for beginning hydro. Maybe a project for later, when you’re more experienced.
  • One-part solutions are simple and easy but are not flexible. Two-part and three-part solutions allow customization and experimentation and give better results.
  • K.I.S.S.: Use the same nutrient solution that NASA does, the best: General Hydroponics (GH) Flora Series Nutrients. And forget the mixing charts on the bottles. We’ve figured it all out for you in the next section here.
Hydroponic solution basics -  a primer on nutrients-  Pinterest image
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Stella and Simon, a couple of back-to-the-land, baby boomer enthusiasts, have embraced the world of homemade hydroponics on their three-acre plot of Florida piney woods. Their journey began after drawing inspiration from Epcot Center’s hydroponics exhibit, and they've delved into various hydroponic methods, experimenting with different systems, configurations, and crops both indoors and outdoors. Their expertise culminated in the creation of an innovative homemade hydroponics greenhouse, documented in their book, Simon’s Super Simple On-the-Grid, Off-the-Grid Hydroponic/Aquaponic Survival Greenhouse.

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