Hair Algae Eaters

[Llewos]

Rainford's/court jester gobies are supposed to be good for filamentous algae.

[gregzz4]

You could also consider snails

Mexican Turbos do a good job, but don't live long
Indonesian Turbos do well too and apparently live longer

I've tried both and the info seems correct so far as my Indo Turbos are still alive, whereas my Mexis only lasted a few months

I also used Strawberry Tophat snails and they did a good job too. But they are even bigger than Turbos and poop big turds that collect on the sandbed