I'm not the expert that a lot of folks here are, but my understanding is that more plants make things easier when it comes to algea. Although you may be overstocked, the tank is clean ( according to the numbers given), so your maintenance is good, I would cut the food in half unless the fish start fighting. I usually don't feed at all during the blackout, the fish will be fine for four or five days without food. and cut your light back to 8 or 9 hours a day max, once the bloom is killed.
You will still have to kill off the green water, it won't go away otherwise, but something to bear in mind is that it doesn't hurt your fish to live in it. To clean algea off plants and ornaments, mix a bleach solution at 19 parts water 1 part bleach, and swish everything in it for about 10 minutes. Then drop it into a bucket of water with declorinator to rinse it. Clean all the algea off the glass ( and anywhere else) that you can. Do as big of a water change as you and your fish can stand. And then cover the tank with a banket, cardboard or something so no light can enter for about 4 days 5 is better. As said, I like to do a daily water change during the blackout to help remove the dying algea. You will also want to keep an eye on your filter media to make sure it doesn't plug up, and rinse it well (in tank water) at the end of the blackout period to remove any build-up of dead algea. after the blackout, your tank should be algea free. A little less light, and more plants if you can, and you should be headed in the right direction. Look for fast growing plants that eat a lot of nutrients. I'll stop now and let the experts take over.
HTH
