Hey guys,

My wife has noticed that the Bio balls that we are using in our Aquarium are always slimy.

She asked her dad who is a Mechanical Engineer, and a Goldfish afficionado, about the Bio Balls. Well, accdg. to my father-in-law, they may seem Good Bacteria. However, Bacteria are still Bacteria.

Good Bacteria can also mutate into a Harmful bacteria. What can you say about this?

Is there any scientific site that will explain the use of Bio-balls? and its origin.