How to Control Aquarium Algae
How to control aquarium algae?
The growth of algae is a fact of life that every aquarium owner will face sooner or later. Some algae are normal and healthy, but excessive algae growth can be dangerous for fish and plants.
What causes excessive algae growth?
Like any plant, algae need three elements to thrive: water, sunlight, and nutrients. If there is an excess of any of these, algae will grow rapidly and become a nuisance.
Obviously, you cannot remove water from the aquarium, but you can control the amount of light and nutrients in the water. Here are common reasons for excessive algae growth:
Lighting – excessive photoperiod and inadequate spectrum
Aquarium placed in direct sunlight
Water changes
Use of water with high nutrient levels
Preventing Algae Growth
Knowing the causes of algae growth is half the battle. Here’s what you need to do to prevent excessive algae development.
Reduce lighting – Do not place the aquarium in direct sunlight, even for part of the day. Sunlight can and will promote algae growth. When using artificial lighting, ensure it is not stronger than necessary and does not exceed eight hours per day. Use a timer to turn the lights on and off consistently.
Feed less – Most aquarists tend to overfeed their fish, leading to increased phosphate levels in the water. Feed in small portions and make sure the fish eat everything. If food is not consumed within five minutes, always remove any leftovers.
Water changes – The single most important way to prevent algae is to perform regular water changes. Replace ten to fifteen percent of the aquarium water each week to keep nutrient levels low.
Know your water – Test your water source. If it is high in phosphates, consider using phosphate removers or finding an alternative water source. It’s also good to test for nitrates, as some water sources have elevated nitrate levels.
Remove algae – If you see algae starting to grow on the glass, rocks, or other hard surfaces of the aquarium, remove it. Wipe the glass, take out and clean rocks, and vacuum the gravel during water changes.
Keep live plants – Live plants absorb many of the nutrients that algae rely on to grow. Fewer nutrients mean less food for algae.
Clean-up crew – Introduce algae-eating fish and invertebrates into the aquarium to help control harmful algae species.
Types of Algae
Do you already have algae in your aquarium and need to get rid of it? Identifying the type of algae will help determine the cause and the solution. Here are the common types of algae and how to eliminate them.
Brown algae – Also known as Gravel or Silica algae. Common in new aquariums, it forms layers that can be easily wiped off. It is usually harmless and will eventually disappear as the aquarium matures.
Blue-green algae – Also known as Slime or Smear algae, it is actually a cyanobacterium caused by excess nitrates and phosphates. It can spread rapidly and cause significant damage. Proper water maintenance helps, but if your water source contains phosphates, you may need special treatments to remove excess nutrients. Erythromycin is also effective against blue-green algae.
Red algae or beard algae – This is one of the most challenging algae types and typically appears on plants. A short dip in a weak bleach solution (5–10%) for a few minutes often kills this type of algae.
Green algae – Also known as hair, filamentous, or spot algae, this is a normal and beneficial type of algae that most aquariums will have to some degree. As long as the aquarium is well-maintained, it will not grow to problematic levels.
Green water (Algae Bloom) – Caused by the rapid growth of microscopic algae suspended in the water, this is one of the most frustrating algae types to remove since it cannot be wiped or scraped off like other algae. Water changes are generally ineffective because the remaining algae quickly regrow. Using a diatom filter or completely blocking out all light for a few days is usually necessary to eliminate green water.