OK, now I think I have a problem with my filter

[kyarnkid]

I have a Sandman filter, I know it is discontinued but I have been told it is a good filter.
In the bottom of the filter there is sand. The filter works when the sand is churning, at least I think. I am so confused why there is even sand in it, what does it do, whats its purpose?
Well should I just get a new filter since this one is discontinued? I don't want to if I don't have to? Can someone tell me how a Sandman works?
I have it running right now but I do not have the second chamber that houses the sand completely open, I just have it barely open. The sand runs better like that.
Please give me some advice?

 

[broomer5]

kyarnkid,
I've fiddled around with the Sandman filters before. I wasn't too impressed. If this is the only filter on your 55 gallon tank, I would consider adding another filter, letting both run for a few weeks, then eventually ditching the Sandman.
Here's an interesting product review article I found that may answer some of your questions. This link may removed from this post
Brian
http://www.theaquarians.net/Articles...man_filter.htm