HI. It's been years since I had an aquarium set up and I know there have been many product improvements made since then.

For Christmas, I am getting my son (14) started with his own stuff (10 gal.) and was wondering about filtration. I have liked the Penguin (I think that's it) filter with the biowheel and thought that's what I would start him with.

But what about under-gravel filters? Are those still in use and are they necessary for a healthy tank? Is their purpose to keep the gravel clean and/or to provide for beneficial bacteria (which is what the "Biowheel" does)?? Advice?