On my 30gal planted I have diy co2 and i use both a glass defuser and the ladder.... maybe it just depends on how your producing your co2? OR maybe it depends on if you use a plastic bottle or what.... im not sure... Either way, a glass difuser works for me....the glass difusers won't work with diy co2. you should get the hagen bubble lader, or a powerhead with venturi. these are the two best bets for diy. I like to keep lots of floating plants right over the hagen bubble ladder, like they do in the chinese lfs. none of the bubbles really make it to the surface, they all hang under the leaves.