This is an effective approach for removing algae on hardscape: wood and rocks. Avoid this method for plants.
This is our usual approach to treat algae on plants. To increase effectiveness, pause the filter during spot-dosing (just a minute or however long it takes you to spot-dose:) And don't forget to turn the filter back on! Avoid this method for treating algae on Mosses, Liverworts (Riccardia and Riccia etc.) and Vallisneria (Tape Grass).