Subject: What are the most harmful household chemicals to the ocean?

For my science fair project, I am conducting an experiment on how certain 
household chemicals (Drain-O and Dishwashing Detergent) affect salt water 
environments.  As part of my research, I need to consult with an expert on my 
experiment.  Here are my questions:\

2.	Could you give me some examples how chemicals affect the ocean 
environment?
3.	In the container of salt water to which I am adding a small amount of 
Drain-O, the salt has settled on the bottom of the container.  However, this 
has not happened to the control container or the container which has the 
dishwashing detergent added.  Could you provide me with an explanation of why 
this is occurring?

Thank you for your help.  I look forward to your reply.  

Re: What are the most harmful household chemicals to the ocean?