Terrariums are full of life and accumulate dirt over time. Some dirt is not easily removed with water alone. In addition to conventional cleaning agents, vinegar is a well-known means of removing stubborn stains. The question arises whether the pungent smelling vinegar is also suitable for terrariums or whether it is harmful to the plants in them. To be brief and to the point: Yes, you can use vinegar, but you have to be extremely careful in any case. Especially when it comes to a closed terrarium. I'll explain why now.
In this article I only describe why you should not use vinegar. Here you will find tips and tricks on how to clean a closed terrarium.
Vinegar is really acidic
If you use vinegar to clean your terrarium, you will make the soil in it very acidic in the worst case. You have to be very careful that no vinegar gets on your plants or flows into the soil. If you do, the growth of your plants may be affected or your plants may wither completely.
Even though vinegar may not taste sour at first, but rather smells pungent, it has a very acidic pH value. This has nothing to do with the taste itself, but refers to the number of hydrogen ions in an aqueous solution. However, this does not mean that at a pH of 1 there are only half as many hydrogen ions as at 2.
pH values explained
The pH value is a scale from 0 to 14 and indicates how many hydrogen ions are present in a solution. The middle of the scale is therefore exactly 7 and this is also our starting point. A pH value of exactly 7.0 is neutral and corresponds to pure, distilled water. All values below that are called acidic. Anything above that is called basic or alkaline.
It is important to note that the pH scale is not a linear scale, but a logarithmic one. Strictly speaking, it is based on the logarithm of ten. Simply put, this means that a pH of 1 is ten times as acidic as a pH of 2, which in turn is ten times as acidic as a pH of 3.
Der pH-Wert gibt die Menge an Wasserstoff-Ionen umgekehrt an. Das bedeutet, dass bei einem sauren pH-Wert (< 7) mehr Wasserstoff-Ionen vorhanden sind als bei destilliertem Wasser und bei einem alkalischen pH-Wert (> 7) mehr. Schauen wir uns die gesamte Skala an, stellen wir fest, dass ein Stoffgemisch mit einem pH-Wert von 1 ganze eine Million mal mehr Wasserstoff-Ionen hat als ein Stoffgemisch mit neutralem pH-Wert.
Here you can learn more about pH value. To understand Wikipedia's explanation, you probably need to study chemistry.
Some plants do not tolerate acidic soil
Most plant species like a slightly acidic pH that stays close to 7. Only a few plants can withstand pH values below 6. After all, that is already 10 times more acidic than neutral. Even small changes in value make huge differences here.
The pH value of the soil has no great influence on how well nutrients can dissolve in the water. The fewer nutrients that can dissolve in the water, the less the roots of your plants will absorb and thus grow worse. I've written about the problem of nutrient deficiency before in the article on how a closed terrarium works.
Plants that like alkaline soils
There are some plants that particularly hate acidic soils and even grow better in alkaline soils. You certainly know some of them. Here are three examples.
Lavender grows quite excellently in alkaline soils and does not do well with acidic soils. According to the spruce, a pH of 6.7 to 7.3 is suitable for lavender.
A beautiful plant with small leaves and red flowers that is well suited to alkaline soils, but definitely not acidic, is the Cotoneaster horizontalis. This grows best at a pH of 6.75 to 7.5, making it find acidic soils even more unappealing than lavender.
The biggest enemy of acidic soils is the genus boxwood, which find pH levels below 6.8 quite horrible.
Plants that like acidic soils
Other plants are not quite so fussy and can tolerate lower pH values. However, you will find that none of them can cope with a pH value of 3 (as vinegar has).
Gardenia is characterized by beautiful white flowers and originates from soils with a pH of 5 to 6, so it can certainly withstand more acidic soils than lavender, for example, but vinegar is still 100 times more acidic than the plant likes. So you would have to dilute vinegar with water in a ratio of 100 to 1 to use it safely as a cleaning agent. Then you can just use warm water directly to clean your terrarium.
Carnivorous plants are also a super example of plants that do well in acidic soils. I've described this before in the article on carnivorous plants in closed terrariums. Because the bog soils they come from are so acidic, they have evolved to get their nutrients from insects or even larger animals.
Cleaning agents are much worse
Although vinegar already has a very low pH value of 3, it is completely eclipsed by conventional cleaning agents, such as toilet cleaner. pH values of 1 are not uncommon for acidic cleaning agents. This makes them 100 times more acidic than vinegar. You would have to dilute them by a factor of 1 million to 1 in order to bring plants into contact with them safely. But then, of course, this has no effect at all.
Summary
Vinegar has a very low pH of 3 and should not be used for cleaning terrariums. This makes the soil acidic and the nutrients it contains cannot dissolve as well in the water. Although some plants can cope with low pH values, that of vinegar is far below.
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