I have a 8 gallon tank that has a built in filter, and is overrun with green water, I have tried large and small water changes and no light, the light worked well but as soon as the light is back on for a day the alge is back. I have taken out the fish and put them in a better filtered tank. I want to use this one for something smaller but I want to have the green gone. I am thinking of putting in a bit of bleach and letting it just run through the filter for a few days, to kill the alge. Then do a 50% before I add any fish again. Any objections or suggestions?