Raking works best on string or matted algae (string algae looks like long green hair, and matted algae looks like a spongy mat of string algae). Take care not to bump any fish near the surface with your rake. Otherwise, they’ll remain safe and sound! To manually remove algae from a rock or pond wall, scrub the algae off with a firm brush (avoid wire brushes so you don’t scratch your rocks). This is a short-term solution that doesn’t prevent more algae from growing back.
8 ounces (230 g) of barley straw can treat about 1,000 gallons (3,800 L) of water. For smaller ponds, buy a mini-bale, pellet, or liquid version of barley straw. Research suggests this works better for green algae (a pea-soup looking algae caused by microscopic plankton) than string or matted algae. Barley straw is organic and eco-friendly—perfect for ponds with fish in them.
A 1 ounce (28 g) tablet works for 1,000 gallons (3,800 L) of pond water. An initial dose in the spring will help prevent algae growth in the first place. Monthly or bi-weekly maintenance doses are usually recommended. This works best in smaller ponds and is more effective when paired with an aeration system.
Aerators and fountains are available at most home improvement stores. This method will need more maintenance than others and is an added electricity expense.
UV bulbs need to be replaced every 6-12 months (they get weaker over time). UV treatments work best in clear water. Install it in springtime before the algae blooms or clear out as much algae as you can with other methods beforehand. Don’t use a water clarifier to clean up the dead algae during your UV treatment since clarifiers can clump fishes’ gills together.
H2O2 is a more recently discovered anti-algae method. Copper salts are more traditional and can be fish-friendly, but are lethal when used incorrectly.
Aquatic pond dye can be found at most home improvement or pond shops. The amount you need depends on the volume of your pond (check the label of the dye to see how much water a bottle can treat). Adding dye makes it harder to view fish and frogs in your pond than in clear water. Blue dye is most effective at countering green and planktic algae. [9] X Research source
Add enough plants so that 50 to 70% of the pond surface is covered. Pond-loving plants are available at gardening stores and nurseries. Ask about which plants grow best in your climate. Add extra shade with umbrellas or sun sails around the sides of your pond.
Getting your fish on a consistent eating schedule can help reduce wasted or uneaten food. When temperatures are consistently below 45 °F (7 °C), stop feeding your fish. Their metabolism slows way down in winter and they can live off of whatever organic matter is already in the water.
Siphon matter from the bottom of the pond away with a pond vacuum, still making sure to move slowly so you don’t spook the fish.
Buffers are completely fish-safe and add a nice decorative element to your pond, too. Using plants as a border will attract all sorts of beautiful butterflies and birds to your pond. A border will also stabilize the shore of your pond and prevent erosion over time.
