Chlorophytes or green algae are single celled plants, containing chlorophyll in order to photosynthesise and moreover we have them to thank for breathable oxygen as much if not more than any other species of plant. read more
Well algae is a plant and as such it really only requires some light and dissolved carbon dioxide (and prolly some micronutrients). So fish absorb oxygen from the water and pass carbon dioxide into the water, so that might help. read more
Algae is often introduced into your aquarium by fish and live food, and it comes in several colors: Blue-green algae (caused by poor water conditions) can form a layer on all of your decorations and substrate, and if your fish stop swimming for a few minutes, they start to resemble a moldy cupcake. read more
If you’re letting your fish stuff themselves to the gills and watching a lot of excess food fall to the floor of the tank or get sucked up by the filter, you are creating two great food sources for algae: fish waste, and waste from decaying fish food. read more