Will plants watered with grey water from a washing machine grow faster than those watered with regular water?

Question

I have a science experiment -grey watered seeds versus tap watered seeds-which grows faster?

Answer 1

Detergents were once high in phosphates, one of the three major plant nutrients, but they now have very little or no phosphates due to environmental concerns.  Grey water is not toxic to plants, we wash ourselves and our clothes in these detergents.

Grey water may contain bleach and possibly other things which may alter soil pH, but I don't think it will cause plants to grow faster.  This is an interesting topic and I hope you let us know how the experiment turns out.

http://www.grist.org/advice/ask/2006/09/...

http://www.lenntech.com/aquatic/detergen...

Answer 2

The grey water will likely make the plants grow slower, as the chemicals in the laundry detergent will affect metabolism in the plant.

Answer 3

my prediction is that the grey water plants will grow faster if you're not using a toxic detergent.  You're giving them more nutrients and there's something about certain detergents that encourage growth, but I can't remember what it is and I'm too sleepy to look it up.

Answer 4

The grey water contains the soap or detergent which is toxic for the plants. So donot try that.