Water quality is one of the most important parts of carnivorous plant care. Many commonly cultivated carnivorous plants are adapted to nutrient-poor habitats and can be damaged by the gradual accumulation of dissolved mineral salts.
Why Tap Water Can Cause Problems
Tap water varies considerably between locations. It can contain calcium, magnesium, sodium and other dissolved substances. Repeated watering with mineral-rich water can allow salts to accumulate in the growing medium and can eventually damage sensitive plants.
Reliable Water Choices
Rainwater collected from a reasonably clean source is commonly used. Reverse osmosis (RO) water is useful for larger collections, and distilled water is also suitable.
What About Bottled Water?
Do not assume spring or bottled drinking water is low in minerals. Many bottled waters deliberately contain dissolved minerals, so the label or a water test is more useful than the word “bottled”.
What Does a TDS Meter Tell You?
A TDS meter provides an estimate of dissolved solids and is useful for comparing water sources, but it does not identify which minerals are present. There is no single TDS number that is ideal for every carnivorous plant species and growing method. As a practical rule, low-mineral water is preferred for the commonly grown bog carnivores that are sensitive to salt accumulation.
If Mineral-Rich Water Has Been Used
Flush the pot thoroughly with rainwater, RO or distilled water. If the growing medium has accumulated substantial mineral deposits or has deteriorated, replacing it with fresh appropriate medium may be necessary.
Using reliably low-mineral water avoids a major preventable cause of long-term carnivorous plant decline.
