Now, this is a different question about watering plants. As pointed out in the previous article filtered water really doesn’t impact plants at all, as long as the water being filtered is not toxic. Purified water however is a different story. From previous articles you may have learned that pure water is aggressive to dissolve anything it comes into contact with. In other words, it will attract any free electrolytes in the soil or even in the plants that uptake the purified water.
A couple of crazy things can happen if you water your plants with distilled or deionized water. Some of the things are good, and some are bad. What actually happens to your particular plants depends on a variety of factors.
- The pure water will tend to dissolve and hold the fertilizer and nutrients in the water. Then when the plants “drink” the water, they will get a good dose of food.
- If the plant is over-watered, the pure water will take a lot of the nutrients from the soil and drip away, or seep into soil away from your plants. In this case using pure water can deplete your plants of nutrients.
- If you are growing plants hydroponically, pure water could cause your plants to swell, and the internal cells to rupture, thereby killing or severely damaging your plants. What happens is the pure water pulls electrolytes out of the plant cells and the pure water, under what is called hyper-osmotic pressure runs into the plant cells causing them to swell. The purer the water, the more dramatic the damage will be.
The bottom line here is that you really don’t need purified water for your plants. It may do more harm than good; including increasing your nutrient bill, or exploding your plants.