Hydrocephalus
Aquarium Advice Apprentice
i would take a syringe and inject the liquid near the algae, however, i never did it with the filter off.
it is primarily a carbon source and won't work like peroxide.
Start off slowly, double dose twice the first week then double dose every other day until it turns the algae red, return to 2x dose a week until clear, then continue as package directs as maintenance, I have dosed this stuff to quiet high levels with plants and shrimps with no problems (except for the algae, it died)
Try to get the big bottles, way cheaper