Hi i have had my tank which is 260L for 8 months now, i have two tiger oscars (6 months old), one small phantom pleco,and two clown loach, all the water tests i have done are at the right levels but the water in my tank is green, i believe this is called algae bloom. i change the water once a week without fail and in the last few weeks i have been doing a 50% water change but still after two days the water starts to go green again. can you please advise me on how to get rid of this problem. many thanks.

you can try to reduce the amount of time the lights are on in your aquarium. algea needs light to grow so therefore no light no growth and keep up the water changes.

this worked for me

As necromancer says algae needs light to grow. You dont need a light on your tank, we only put them on so we can see the fish. How long do you have your lights on for. Reduce it to about 4 hours a day. Also is your tank is a position such that it gets lots of sunlight on it, if so try closing the curtains to stop this