What things should I consider regarding inflow of household grey water into a fish pond?

What is greywater?
Any water that has been used in the home, except water from toilets, is called greywater. Dish, shower, sink and laundry water comprise 50-80% of residential "waste" water. This may be reused for other purposes, especially landscape irrigation.

How can I determine if "biodegradible" soaps and detergents would harm fish?

Thanks