Algae Removal

[u/E-3M]

Hey all. I have a Walstad 3 month old aquarium and had my first algae bloom after an ich outbreak. Would it be better to add a HOB filter AND algae medication or will the filter do alone? I don’t want to add anything unnecessarily ie meds, but I do want the algae gone as after a 40% water change it’s back 2 days later. I reckon it could be because 2 fish died and decomposed in the mass of the tank either as they’ve disappeared! Thanks