Green water

[Merbeast]

The very best way to rid yourself of an algal bloom is to cover the tank (to not let any light in at all) and do not feed or uncover it for a week. The fish will survive, and the algae will not. Reducing the light will do it over time, but not as fast as making the tank completely dark for a week.

 

[Nyquil Junkie]

Get a UV sterilizer since the greenwater will come back once you turn the lights back on. (sometimes).

For a 29 gal tank a JBJ submariner 7watt unit will be good.
in about 3-4 days you will have crystal clear water.
plus it kills any disease parasites and bacteria in the water

 

[Merbeast]

Get a UV sterilizer since the greenwater will come back once you turn the lights back on. (sometimes).

Not necessarily. A well maintained aquarium will likely have attached algae, but will not have algae blooms. Time usually takes care of algae blooms.