What is the image on the left, and what does it mean?

The image on the left is a pH test taken from the hydroponic tower’s mineral water. As shown, it can be inferred that the colour of the liquid is approximately 7.5 . To understand what this means, we need to take a step back, and learn about what the concept of pH levels is!

What is pH, and how is it related plant growth?

pH is an abbreviation for the term power of hydrogen. The pH scale measures how acidic or basic something is. Depending on it’s acidity or basicity, it can be placed on the pH scale, which ranges from zero (most acidic) to fourteen (most basic). r

pH levels are essential to plant growth.

The optimal soil pH levels for plants is between five and six.

Low pH soil means that it has a high concentration of positively charged hydrogen ions. Many elements are not attracted to this pH range, however metals like iron, metal and magnesium are soluble in low pH levels. These metals are incredibly toxic for the plants.

High pH soil is also bad for plants. It has a high concentration of negatively charged hydrogen ions. This attracts calcium, which in turn prevents phosphorus (an essential nutrient for plants!) from being absorbed by the plants. Toxic elements which impact plants in high pH soil include molybdenum and boron.

What does this have to do with hydroponic towers?

Although hydroponic towers do not require soil, they require a mineral solution that provides nutrients to the plants! The best pH levels for the mineral solution lie between 5.5 and 7.0. To test this, we use drip phenol red into a testing tube with the mineral solution inside, and depending on the colour it turns we can determine where it lies on the pH scale! Going back to the first image, we discovered that the mineral solution was far too basic, and had to add pH reducers to the solution. The image on the left is a retest of the pH, which is now at 5.5, the optimal level.

Always check pH regularly!!

It is important to consistently check pH levels, at least twice a week to ensure that the plants are growing in a healthy environment! If the pH is off, use the pH reducers or pH increasers as instructed, and then retest the pH a few hours later.