Algae ID

[starreef05]

Hello all. I cleaned the return heads and it’s already making comeback after 24 hours. Please identify what it is. When it is too much and starts sticking out of the water, it turns into yellow slimy substance.

 

[starreef05]

Will post another pic when it gets more growth.

 

[ncaldwell]

That's what my dinoflagellets on my returns look like

 

[starreef05]

That's what my dinoflagellets on my returns look like

I thought they spread everywhere like crazy. They only form on my returns. How do I correct this?