I have small herb garden (parsley, coriander mint and basil) that is watered from below by a hydrophilic filter using capillary action from a reservoir. This filter allows water soluble nutrients to be fed to the herbs.

The manufacturer of the filter use a special propitiatory additive in the filter that allows for excellent water flow. I need to know the the harmful implications of the material as they have stated the unknown "additive in the filter is not FDA approved". They will not tell us what additive is to protect their intellectual property.

My question is that will the herbs absorb the additive regardless assuming the additive is leaching into the water. Say that 1 ppm (parts per million) of substance X is in the water. Will the herbs absorb that and propagate it to their leaves. If so how much of the substance? (very rough estimate will do)

TIA, Dave


1 Answer 1


You'd have to test it. Plant roots naturally pull poisons like heavy metals out of the soil through water. These are called metallophytes, and can even be classified into what're called hyperaccumulator plants. The use of plants to remove harmful substances from the soil, air or water is called phytoremediation.

The process of absorbing harmful substances, however, relies on the structure and size of the substances involved because the substances must enter cells. We know from elementary biology that cells only allow molecules of certain properties to pass their cell membranes. Since the filter additive in question is an unknown, it's hard to say if a plant would absorb it. It's also hard to say if it's harmful to you, or if it even gets into your water. Testing for a chemical of unknown behavior requires some analysis like mass spectrometry (fair example).


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