Alright....we have a brand new (2 months old) 1 acre pond, and over the last couple days while swimming in it we have started smelling a sulfur smell...after hours of research, I believe we are going need some aeration. It has also developed about 1/2 of what seems like muck on the bottom. Its real slimy. If that’s the case what brands do you recommend and how many would you think I need? Thanks in advance.