Types Of Algae In Saltwater Aquariums

Types Of Algae In Saltwater Aquariums


Perhaps you have heard, seen or touched algae in the past. If you are setting up a new saltwater tank, it’s important to understand the different types of algae in saltwater aquariums. There is no denying that algae growth is something natural in saltwater aquariums. Did you know that there are over 30000 million types of algae that you can find on earth? Others are good to keep, others bad. What is algae anyway?

These are photosynthetic living organisms that arise in water habitats. Yes, they adapt in all water conditions- from freshwater to salt, the pole to the equator. They also grow in different sizes from small (microscopic) to seaweeds of about 200 feet. When it comes to reproduction, these organisms grow at a fast rate. Of interest, they play an important role in the food chain. In fact, they are primary producers that give oxygen to aquatic organisms.

You can have beneficial and nuisance algae in your saltwater tank. Some people prefer to keep beneficial algae due to the benefits, while nuisance algae should be removed as there is no benefit and can be harmful to keep.

Algae is also referred to as microalgae and macroalgae.

Microalgae are small microscopic aquatic photosynthetic plants that require the aid of a microscope to be seen. Macroalgae are large aquatic photosynthetic plants that do not require the aid of a microscope to be seen.

Well, that is all about algae. If you own an aquarium, expect to see them. Most algae get introduced into the aquarium while some come with water from other aquariums. Just like your flowers in your garden, algae need light and nutrients to survive.

Scroll below to browse different types of saltwater algae and how to get rid of them.


Click here to read: What are the proper levels for saltwater tanks?

Diatom Algae

They are the most available algae on earth. Diatoms always suspend on the surface of the water as brown powdery particles. Of course, they feed on silicates in your aquarium and can pop up when the aquarium is new and not finished the cycle process. Not only is diatom algae unsightly, but it can be harmful if it gets out of hand.


Manual removal includes wiping off the diatoms with a glass cleaning magnet like the Flipper. Where you can’t access deep affected areas, you can use a toothbrush. You can also use a water change hose to siphon the algae out of the tank. It’s important to use RO/DI water to help prevent diatoms. Snails like Nerites or Ceriths can be used to effectively remove diatoms.

Cyano (red slime)

Cyano a.k.a cyanobacteria are common algae that occur in most aquariums. It is a nuisance algae and should be removed as it is harmful. Some of its causes may include:

  • Presence of nutrients such as phosphate
  • Poor water movement
  • Warm water. Cyano grows rapidly in the warm environment than in cooler environments
  • Not using RO/DI water
  • Overfeeding
  • Poor skimming
  • If the alkalinity of water is low. High water alkalinity discourages Cyano growth


Manually remove the algae carefully as you don’t want it to spread. Wipe off the suspended Cyano and siphon out as much as possible. Sand grown cyano will be uprooted and discarded. Since these species grow at high rates, it is recommended to increase water alkalinity. Remove also any rotting substance that may be leading to Cyano growth in your aquarium. Use a phosban reactor with phosphate removing media to reduce phosphate nutrients in your aquarium. Reducing your lighting for a blackout period can also help.

Green hair algae


Types Of Algae In Saltwater Aquariums


Green hair algae are simple species with easy to know features. These finely textured algae are small therefore their level of distinction needs a microscope. So, how to distinguish them from other look-alike algae? Well, green hair first is not coarse. When touching them, they can easily spread into parts. If you remove these GHA from the water, they are likely to lose form. GHA is caused by using tap water, high levels of nitrates and phosphates, poor nutrient control. Excess lighting also contributes to the formation of Green hair algae.


Getting rid of these algae is quite simple. They are easier to be pulled out or scrubbed using a toothbrush. Use Turbograzers, Sea hares, Blue leg hermits and many others.

Turf algae

Turf is wiry algae with thicker blades than GHA. You will found them sprouting from the rock like root structures. Controlling them is hectic if not done as soon as you can.


Uproot the turf algae that grow with a root. Manual removal is the best way to combat Turf algae. You can add clean up crew like emeralds crabs, snails. They love to eat it.


Marine Depot Aquarium Supplies

Green Bubble algae

The Green bubble is fast-spreading algae that belong to the Valonia genus. It won’t take a few weeks before you see them covering the whole aquarium. For this reason, deal with them as soon as possible before it multiplies throughout the aquarium.


Slowly without spreading them, manually remove them by plucking them out. Do not break the bubble as the spores will release into the tank causing many more to form. If you can remove the rocks or anything else with Bubble algae, it will be easier to remove. Once you finish, add emerald crabs to eat any other remaining algae.


They can also be called brown slime algae. Dinoflagellates are quite devastating. Why? They are killer organisms. They can destroy organisms like nails and feed on them. The snot-like growing substance, Dinoflagellates occur in sand or rock with air bubbles landed on them.


Dinoflagellates are difficult to remove. Manual removal is your best option but other things to try include:

  • Use a fine filter sock
  • Increase the nutrients in your tank
  • Blackout your lights for 72 hours
  • Use a UV sterilizer
  • Adjust your PH level. 8.4PH is a good level to help prevent dinos.


Coralline algae


Types Of Algae In Saltwater Aquariums


These are purple algae that if left can cover anything like a rock in your aquarium. They are another hard to remove algae and can encrust everything in your tank. Coralline algae are often desired by saltwater hobbyists as it looks very natural and colorful.


Get yourself a blade tool (algae scraper in this case). The Flipper does a great job of removing Coralline algae. You can also use snails and Urchins. They love to eat it.