I've had an aquarium for a year now that has worked well with out a filter. However recently I had a bloom of green floating algae. I turned the lights off for a week, did water changes, tested the water. However I can't find a cause. My conclusion is it's the fact that a plant species I had I recently took out because it wasn't doing well. Now the obvious solution is to get more plants. However how do I get rid of the agae? I can't afford to turn the light off for another week the plants suffered for that and it only sort of helped anyways. Do I need to get a filter?