Algae blooms...
Primarily are caused too much light and/or for too long, combined with a high level of nutrients in the water.
Fix these and the algae will not survive.
Some ways to eradicate algae blooms....
(1) This is the only permanent solution.
Lowering amount of light and nutrients* in water, also lower temp -77'f, algae does better at temps above 77'f.
Lights on for no more than 8hrs unless growing plants, preferably 6hrs max. Reduce feedings. Increase PWC's (partial water changes).
*Dissolved solids, NO3(nitrate) and PO4(phosphate) are the most common.
(2)A UVS (Ultra Violet Sterilizer), kills the algae and some types of other free-floating unwanted biologicals. A algae bloom is still a possibilty with UVS if not set-up properly.
(3)A Diatom Filter, removes algae from the water, but is not a permanent solution.
(4) Filtration using a 'Micron' pads will remove algae, but is not a permanent solution.
(5)A 'complete blackout' of the tank for at least three (3) days, sometimes longer will kill the algae bloom, but it is not a permanent solution. This option will not adversely affect your fish, but you can move them to a holding tank if you want to.
(6) Algae-cides, use carefully, preferably don't use'em at all as they can cause harm. Once again not a permanent solution.
Goodluck and HTH.