Algae Eaters are a fish keepers favorite way to take care of the green stuff. Here are just a few that can help out. Just be careful not to put too many in your tank. If there are too many algae eaters and not enough algae, they will starve.
Plecostomus – family Loricariidae – The classic algae eater. Many species available with some being much more effective than others. They help with glass, gravel and ornaments. I recommend the mountain stream (a.k.a. rubber) plecostomus for functionality. Royal or Leopard pleco for aesthetics.
Otocinclus – Otocinlus spp. -Great help for keeping small ornaments and plants clean.
Siamese Flying Fox - Crossocheilus siamensis- One of the few fish that eats thread algae (a.k.a. string algae, beard algae, hair algae).
Chinese Algae Eater - Gyrinocheilus aymonieri – A colder water species with a pretty good appetite for algae. Has a tendency to be a bit nippy.
Snails – Pick a snail, any snail. Almost all are good algae eaters. They also have a tendency to reproduce like guppies.
Algae Eating Shrimp – Caridina spp. – Great little critters. They will eat almost any type of algae. Should be kept in a very peaceful tank as many fish see them as food.
Live Plants. While they don't eat algae, they do stop algae from eating. Live plants compete with algae for the same nutrients.
Barley Straw. When barley decomposes it releases humic acids. The reaction produced by humic acid, light and dissolved oxygen yields very low levels of hydrogen peroxide, which inhibits algae growth.
Ultra Sonic Waves. Ultrasonic sound devices transmit vibrations through the water that case the vacuoles inside algae cells to resonate and break. These units can be used in larger ponds as a chemical free and environmentally safe way to kill algae without harming your fish or plants.
UV Sterilization. Water can be pumped through a UV sterilizer to not only kill algae but some fish pathogens and parasites as well. These units mount easily on the side of the tank, the wall behind the tank or in the stand.
Salt. Salt can be used to kill pond algae at the ratio of 1lb non-iodized salt to 100 gals water. This works especially well for string algae. Dose three times with twelve hours in between. Be prepared to skim dead algae out of your pond so it doesn't rot and cause problems.