Nutrient concentrates are the most important purchase for the hydroponic gardener, as the nutrient solution is the principal source food for hydroponically grown plants. There have been many advances made in hydroponics over the past few years, and the most important of these has been in the introduction of ready made nutrient concentrates.

As general plant foods and fertilisers are designed for soil gardening, they are not suitable for hydroponic growing. This is because certain trace elements that occur naturally in soil are omitted from these preparations and, if used in a hydroponic system, will not provide the full range of nutrients needed by the plant.

In addition, hydroponic nutrient concentrates go through a further process of refinement, because of the absence of soil bacteria to break down nutrients prior to uptake by the plant.

Nutrient concentrates are usually purchased in a concentrated and soluble form, that simply needs diluting with plain water. Good nutrients are supplied in the form of chelates (key-lates). Once taken into the plant these chelates immediately become active and begin their individual processes. It should be noted that chelates (and nutrients in general) react poorly to extremes in the pH level.

By using these concentrates you have full control over the plants nutritional requirements, something the soil gardener does not have as it is impossible to balance nutrients once they have entered soil. With hydroponics you can give the plant the full profile of nutrients in the correct quantities at all times.

There are various types of nutrient concentrate on the market.

ONE AND TWO-PART PACKS

Nutrient concentrates can be purchased as one or two-part packs, with the nutrient concentrate provided as either a single liquid in one bottle or separated into two bottles.

ONE PART PACK

Only a few manufacturers produce one part nutrient solution concentrates. Some nutrients are incompatible in solution and will precipitate out if mixed, so producing a single solution concentrate requires quite a complex bonding of molecules. Although this will limit the variety of one part concentrates available, they are the easiest to use.

TWO-PART PACKS

Two-part packs are by far the most commonly used type of nutrient concentrate. The concentrate is provided in two bottles, usually marked A and B. These concentrates are continually improving and have made hydroponics accessible to the hobby grower as a perfect nutrient solution can now be made up as easily as making a cup of tea.

GROW AND BLOOM FORMULATIONS

Most manufacturers produce separate concentrates to use in the vegetative (grow) stage and another for use in the fruit/flowering (bloom) stage, as nutrient requirements are very different for these two stages.

In the vegetative stage plants need plenty of nitrogen, which encourages good root, leaf and stem growth, whereas phosphorus and potassium are more important in the fruit/flowering stage.

HARD AND SOFT WATER VARIETIES

Some manufacturers produce both a normal nutrient concentrate and one that contains exactly the same nutrients, but which has been designed to be effective when used with either very hard or very soft water.

Soft water nutrient concentrates contain higher leve’s of calcium and magnesium in order to compensate for the low levels of bi-carbonates in soft water. The amounts of calcium, magnesium and boron are reduced in hard water areas.

SYSTEM SPECIFIC NUTRIENT CONCENTRATES

It is now possible to buy nutrient concentrates that have been specifically developed for use in the different types of hydroponic systems (eg. Ebb and flood). As explained on page 12, the nutrient solution can be run with different maximum conductivity levels depending on the system used.

System specific nutrient concentrates are designed to take this into account, and are particularly useful if you do not have a conductivity meter, and are using the basic method of nutrient solution management.

ORGANIC NUTRIENTS

Contrary to popular belief, excellent results can be achieved by taking the organic approach to hydroponics. Over recent years excellent nutrients have come onto the market which work well in hydroponic systems, and others are being made from nutrients sourced from organic or sustainable sources. This is one area where hydroponic nutrient manufacturers are producing interesting and effective new products.

An acid solution can be used to lower the pH of the nutrient solution and natural enzymes can be used to prevent root disease etc.

CUSTOM NUTRIENTS

Custom made or bespoke nutrient concentrates are at the cutting edge of hydroponics and are only really recommended for those wanting to grow competition quality produce or for those with a chronic water problem.

With custom nutrient concentrates, a sample of tap water is sent off for analysis. Grow and bloom formulations can then be made specifically for use with that water source. The conductivity range of the plant, the type of system and the growing conditions are also taken into account to produce a concentrate unique to your situation.

Custom nutrients can be purchased as two part packs and as a three part pack for advanced nutrient solutions. With a three part nutrient concentrate, there is a base part which corrects the pH. This is added first, and then parts A and B are added as usual until the desired conductivity level is reached. The pH should now be around 6, which means that you do not have to add any pH solution.