Powerhead or canister filter for more flow?
I want to improve the C02 dispersal/flow in my 20L. The tank is medium-heavily planted and I have an atomic diffusor at about 2bps. I currently have 2 Aquaclear 30ís on max. Waterline is to the brim to keep co2 from gassing off.
I am noticing some green fuzz algae on plants where the flow is low. I was wondering if buying a small powerhead (Hydor Evo Pico 180, etc.) and putting it above my atomic diffusor would be enough or should I just buy a canister (Eheim 2215, etc). Buying a power would be much cheaper (20$ vs over 100$). Is the canister worth it?
Any other suggestions for a powerhead/canister depending on what route I go?