Some people think that bubble upflow scrubbers only grow slime. This is because waterfall scrubbers can't hold on to slime (the screen just looks empty), and so you rarely see pictures of waterfall scrubbers with slime. They give up and say the scrubber never grew.

A bubble upflow, however, holds on to slime, allowing for pictures of slime, and also allowing for the great filtering that slime can do. Ever seen chaeto reactors getting covered in slime? That's because slime is a better, more aggressive absorber of nutrients than chaeto.

So instead of crashing your chaeto, or thinking your waterfall isn't working, just use a bubble upflow scrubber and grow the slime on purpose.

http://algaescrubber.net/forums/show...he-best-filter

http://algaescrubber.net/forums/show...-slime-screens