My nano tank keeps going crazy

[Tofu Brady]

For the past 8 months my nano tank(20 gallon) has been having countless outbreaks in algae and I’ve lost a lot of my coral, I have slacked out on maintenance some like waiting another 2-3 days extra to do a water change but all that happens is I get algae out breaks and my corals have now all of a sudden bleached please help

 

[Katrina71]

Pics please

 

[Tofu Brady]

I cant seem to get rid of the green hair algae

 

[Tamberav]

Do you have a clean up crew?

What light are you using?

It looks like micro algae that snails and urchins etc would eat.

 

[Thunder_reef]

Parameters? Tank age?