Good fish for frag tank

[Charley75]

What small inexpensive fish would you recommend for a frag tank? I have a 4x2x1 that I am having some issues due to low nutrient levels. Thinking of adding a couple small fish to help.

 

[mpatterson42]

I've never had them myself but I know someone who has saltwater mollies (he acclimated them from freshwater) in their frag tank, he loves them because they're eat algae like crazy.

 

[19Mateo83]

Springer damsel

 

[Charley75]

Bump