Brown-Gold growth

[intarsiabox]

You are correct about it being diatom growth. Just continue to cycle the tank and do weekly water changes and it will go away on its own. The worms are bristle worms. Generally harmless and scavange excess food in the tank.

[RobertScott]

Thanks

[Aqua Man]

I find astreas snails like to clean up the sand, also a sand sifting sea star. But I am not sure they may out grown a 12 gallon tank