I have a friend who is just starting a saltwater tank, and was talking with him about the differences recently. He mentioned that many say that the protein skimmer is the key item for a successful saltwater tank due to its great mechanical filtration.
I did some research and found a nice article on how protein skimmers work on another site ( www.drsfostersmith.com/pic/article.cfm?aid=1321 ) and was wondering if anyone had any personal experience with using a protein skimmer and if so, specifically how well they work for mechanical filtration.
I was thinking that it would be nice if it would help out with my messy puppies, but after looking at the prices on these things want to know more in advance.

Love the site, I think I've read most of it now

to be quite honest, I think you'll be wasting your time having a protein skimmer on a freshwater aquarium. at the end of the day, you're not having to deal with expensive salt or marine water. The water we use in our fresh water aquariums is straight out of the tap and costs next to nothing. To keep the water in good condition and make sure there is no large particles left in the aquarium, it's probably easier to do frequent water changes. A lot of the larger marine aquariums are set up so you don't actually have to do frequent water changes, sometimes only one water change a month.

I am not 100% on this but i think you need a protein skimmer in salt water tanks because the fish waste floats on the top on the water because of the salt in the water. In freshwater tanks the fish waste is mixed in the water evenly. The problem with the fish waste floating on the water is that it stops oxygen getting in, a protein skimmer removes the floating waste. This in what i was told by a fish shop worker