Originally Posted by spoonman
Another reason for water changes is that the salt mix has the essential elements in it that are used up by corals and fish. Newly mixed water replaces those trace elements.
Yep, water changes don't just take out the nasties, it adds the good stuff.
depending on stocking and feeding you can get away with water changes every other week, I do massive changes on my big tank, like 40g or more like every other week.
If you want to improve water quality I would highly recommend a skimmer. They can be a little pricey but after you see what it draws out of your water you'll be amazed you didn't get one sooner. lol
When i was running a canister on my other tank I cleaned it out every other week, those things store up all sorts of nasties and gunk, so at least work on that aspect.