Lawnmower Blenny – Complete Care Guide

The Lawnmower Blenny (Salarias fasciatus) is a fish commonly known in the saltwater aquarium side of fish keeping. This Blenny is also known as the Algae Blenny. It gets these names because of its excellent skills at keeping algae away. However, if your aquarium is infested with hair algae, you will likely need to do work and manually remove it. The Lawnmower Blenny will help keep it down from there. You might want to check out How To Remove Green Hair Algae in Saltwater Aquariums if you’re having algae issues.

Besides their skills at eating algae, Lawnmower Blennies also have fun personalities. This species is herbivorous and generally a very peaceful addition to an aquarium. They spend most of their time grazing on rocks or perching on different surfaces in the fish tank. This guide will discuss the Lawnmower Blenny’s aquarium needs, dietary suggestions, compatible tank mates, and more.

Aquarium Requirements

Lawnmower Blennies will grow to about 5 inches. I recommend keeping them in aquariums that are 30 gallons or larger. However, I do not suggest adding them early into your fish tank. They do best in established aquariums. An established aquarium will likely give them different things to graze on. Stacking different-sized pieces of live rock is recommended. The rock provides additional surface area for grazing, as well as caves and nooks to give this fish somewhere to establish territory, perch, and hide. Sand depth does not matter for this fish because it does not sift sand.

Blennies may jump out of an aquarium. I recommend adding a well-fitted lid on top to help prevent this. They will likely do this when they get spooked or when they dart up for food and don’t hit the breaks before getting out of the water.

Is the Lawnmower Blenny Reef Safe?

The Lawnmower Blenny is generally reef-safe. It should not bother most corals and will not bother crustaceans. There is a possibility of small-polyped stony (SPS) coral and Clams getting nipped.

Will the Lawnmower Blenny Eat Macroalgae?

Macroalgaes should not be bothered by Lawnmower Blennies. Some fishkeepers believe they benefit macroalgae by consuming detritus and other algae that may grow on macros.

Water Parameters

Stability in water parameters is one of the important factors in keeping fish happy. Just like most saltwater fish, the Lawnmower Blenny requires the following water parameters:

• Water Temperature between 72° and 78°F

• pH between 8.0 and 8.4

• KH between 8 and 12

• Salinity between 1.020 and 1.025 sg.

You can keep an eye on salinity levels with many different tools. Check out “Different Salinity Reading Tools for Saltwater Fish Tanks” to learn about the tools. KH and pH levels are often replenished through water changes. Lastly, heaters are used to get your temperature to its desired level.

Food & Diet

Lawnmower Blennies will get quite a bit of food from their environment. They graze on algae on rock, heaters, glass, and many other surfaces. However, algae in the aquarium should not be their only source of food. I recommend providing them pellet and flake food that are focused on herbivores. Also, Nori Sheets are an excellent food source for your Lawnmower Blenny. There are many food options for saltwater herbivores. Take a look at 12 Best Fish Food for Herbivores – Salwater Edition to see some of the best choices.

Tank Mates

Most peaceful saltwater fish will do great with Lawnmower Blennies. This species is not normally the aggressor when it’s small. It becomes less peaceful as it grows. There is a likely chance you’ll get territorial disputes between Algae Blennies and fish that use the same space in an aquarium. Also, you will definitely get fights between the Algae Blenny and fish that have a similar shape. I’d be very cautious adding more blennies into the same aquarium because of this.

A larger aquarium, aquarium with an abundance of rockwork and hiding spaces, usually relieves a lot of territorial disputes. It’s important to create an appropriate habitat for your fish, and not put them in cramped spaces.

Breeding

There is a small chance of finding a pair of Lawnmower Blennies in a fish store. In the likelihood that this happens, they may breed in your home aquarium. CORAL Magazine briefly discusses the success of this here.

Final Notes

Algae Blennies are great fish to keep and they are packed with interesting personalities. They often blend into the rockwork, so it’s always a thrill searching until you find them in your fish tank. They are often used as tools to cutdown on algae in aquariums, which is a big bonus for an already fantastic fish. If Lawnmower Blennies are do not interest you, consider checking out other Blenny Species.