This thing spits out a ton of bubbles and my fish really like it. Its also really easy to hide in the rocks. Also, you can't beat the price.

Pros: easily hides

Cons: none

This is an old favorite. It does a terrific job of oxygenating the water without a lot of bells and whistles.

Pros: Effective

Cons: none

I have never really determined if these things really work or not - do they give the fish more air? Anyway, I think the look cool in the water and the fish love to swim through the bubbles! So, I use them whether they work or not!

Pros: Cool

Cons: none

Sandstone airstones produce wonderful bubbles in the tank. There are several sizes which is good because I have three tanks, all different sizes. These last quite a while and after two or three years they
tend to start to crumble. But they are very inexpenisve and I don't mind replacing them. The fish in the oxygen and I love the bubbles. Good product.

Pros: they really work well

Cons: none

I think it looks neat, however it needs to be replaced every so often because it clogs up.

Pros: looks neat

Cons: clogs up