Hydroponic Nutrient Solution

Since making a hydroponic nutrient solution is a major part of hydroponics, I’d like to spend some time talking about how to get it right.

This can sound like a complicated subject so we’re going to take out all the “fluff” and make it easy to understand.

A good hydroponic nutrient solution is all about the water

Since most people in an urban or suburb type setting will be getting their water from the “tap”, I’d like to spend some time on this.

You generally have two options when using this source,

1) With a filter, or

2) Without a filter.

The type of filter you use will depend on your money and your needs.
I will recommend using a reverse osmosis filter so I’ll be discussing this type of filtration system as well as unfiltered H2O for making a hydroponic nutrient solution.

Making a hydroponic nutrient solution with hard water or soft water

If you plan to use tap water, then the first thing you need to find out, is the quality of the tap water you will be using. This includes finding out if you have “hard water” or “soft water”.

If you have less than 50 milligrams of calcium per liter, you are said to have “soft water”.
The amount of calcium and magnesium nutrients you supplement will vary depending on your situation.

Hard water which is comprised mostly of calcium and magnesium causes scaling. Scaling is the left over mineral deposits that are formed after the hard water had evaporated. This is also known as limescale.

Limescale can clog pipes, ruin water heaters, coat the insides of tea and coffee pots, and decrease the life of toilet flushing units. This is important to know because you will be able to buy some nutrients that are made for “hard or soft water”.

You can learn all about the water in your area by reading the latest water quality report.
You can also get a free test kit provided by most water softening companies so that you can check the water yourself.

What you want to learn:

1) What is the pH of the water coming from your tap?

2) What is the parts per million (ppm) or EC measurement of the water?

Finding this information is best done by using electronic meters. These tools make using nutrient solutions very easy.
Without exact measurements, you’re left playing a guessing game.

When you know what the pH and EC is coming out of the tap, and how to measure the amount of total dissolved solids in the water, you can more accurately make a pH balanced hydroponic nutrient solution ready for use.

Do I need a water filter?

For many years, I and other people I know used no water filter. However without a filter of some kind, you will have little or no control over the quality of TDS (total dissolved solids) in your water.

So in my opinion, your two major concerns dealing with unfiltered water is the chlorine and the pH of the water. As a result, some preparation will be necessary.

A high level of chlorine is not desirable in a hydroponic nutrient solution because it destroys microbial life, so it will be our priority to minimize this chemical compound.
This is accomplished by inserting an air stone connected to an air pump and leaving the water to “bubble” in the reservoir for at least 24hrs before using. Also, add appropriate amount of pH mix when you fill the reservoir with the required amount of water.

During this 24hr period the pH of the water will “settle”, the chlorine will dissipate and the oxygenated water will make life very difficult if not non-existent for the anaerobic bacteria. You will then have water that is ready to use.

Tap Water Method

 

Because using a reverse osmosis system will remove up to 99% of all contaminants, R.O. is far better than using tap water for preparing your hydroponic nutrient solution.

However R.O. systems can be expensive so I’m going to show you how to prepare tap water for use with hydroponics. This is a method that I used with great success for many years when making a hydroponic nutrient solution before I switched over to a R.O. system.

Supplies:

syringe
air tubing
air stone
air pump
reservoir
reservoir cover
pH adjuster

Step by Step

Step 1)
Fill reservoir with 1-10gal of tap water.

Step 2)
Use syringe to add appropriate amount of pH adjuster and mix well.

Step 3)
Insert air stone connected to air pump.

Step 4)
Plug-in air pump.

Step 5)
Leave water “bubbling” for 24hrs before using.

Why Reverse Osmosis?

Tap water will usually bring chlorine and some total dissolved solids (TDS). So depending on how clean you’d like your water to be, you might decide on using a water filter of some kind. Reverse osmosis is hands down the best option for hydroponics.

A good R.O. system will remove 99% of all total dissolved solids and contaminants including chlorine and fluoride. The result is pure clean water with almost 0% TDS and a neutral pH of about 7.0.

A reverse osmosis system will give you the most control over the quality of the water that you use for your plants. This is good for many reasons,

1) Little or no contaminants in the water help to increase the health of your plants.

2) Tap water usually has a high pH which means an R.O. system will allow you to use less if any pH solution.

3) The less TDS you have to start with means you have more control over the quality of nutrients in the water.

4) Pure water with high quality nutrients will give you better tasting fruits and vegetables.

The Downside to Reverse Osmosis

Of course there are downsides as well to using a reverse osmosis system.

The major downside to using a R.O. system is that it wastes more water than it makes.
This can be turn off for those of you who are interested in water conservation.
Another downside is that reverse osmosis is slow. It can take around two hours to make 10 gallons of water.

I would suggest using R.O. for smaller set-ups. If you use more than 50gal per week then I would suggest using tap water or a less expensive water filter that doesn’t waste so much water.

On the other hand if you are working on a large project and you happen to live close to the sea, it’s worth noting that there are industrial type systems available that will clean sea water.

Reverse Osmosis Method

A Reverse Osmosis System is by far your best option for water filtration. Of course if you can’t afford a R.O. system then a cheaper quality water filter will work also. But I recommend learning to use tap water until you can afford to buy a R.O. system.

Supplies:

Reverse Osmosis System
syringe (optional)
air pump
air tubing
air stone
reservoir
reservoir cover
pH adjuster (optional)

Step by Step

Step 1)
Begin filling reservoir with reverse osmosis filtered water.

Step 2)
Insert air stone connected to air pump.

Step 3)
Plug-in air pump.

Step 4) *(optional)
Measure and add desired amount of pH solution and mix well.

Step 5)
When desired amount of R.O. is obtained, water is ready to use.

Keys to Success

The key to success when making a hydroponic nutrient solution with filtered or unfiltered water will be preparation. I suggest taking the time out to make 1 gallon or 4 liters of correctly pH balanced full strength hydroponic nutrient solution.

Write down all the measurements so that when you prepare water you can be ready with the correct amount of pH solution and nutrients. You may get this wrong a few times, but taking the time out to practice this and get it right will be half your battle.

This is the all important question to answer when preparing water to make a hydroponic nutrient solution:
How much pH adjuster (ml) is needed to give the water a correct pH of (*) after the nutrients are added?

*Correct pH varies according to what you are growing.

Take the time out to find out the correct pH and the nutrient needs of your plants. This will go along way when it comes to making a high quality hydroponic nutrient solution.