I have read Why is swap being used even though I have plenty of free RAM? the thread, which was very helpful, however I have 8 gigs of ram installed, (mentioned in the thread as masses of ram), and am still having swap problems.
The ram usage seldom exceeds 4 gigs, but after a few hours the computer becomes significantly sluggish, and any time I check with system monitor, a small amount of swap is in use. The problem seems to be related to Firefox.