How To Care For Chaetomorpha

How to Care for Chaeto & Tips for the Best Results

Chaetomorpha, commonly known as Chaeto, is one of the most popular macroalgae choices for reef tank refugiums. Its dense, green, fibrous structure allows it to absorb excess nutrients from the water, such as nitrates and phosphates, helping to maintain better water quality in your tank. Due to its rapid growth and ease of care, Chaeto is often the go-to solution for aquarists looking for a natural way to manage nutrients without the need for complicated equipment.

Why Chaeto is Valuable in a Reef Tank

Chaeto serves multiple purposes in a reef aquarium, making it a valuable addition to any refugium setup. First and foremost, it acts as a natural filter, pulling excess nitrates and phosphates from the water column. This helps to maintain stable water chemistry, reducing the risk of nuisance algae outbreaks in the display tank.

Additionally, Chaeto provides an excellent habitat for copepods, amphipods, and other beneficial microfauna. These tiny organisms play a key role in the aquarium’s ecosystem, acting as a natural food source for fish and corals. By cultivating a healthy Chaeto refugium, reef keepers can promote biodiversity while improving water quality.

Key Factors for Healthy Chaeto Growth

Lighting

Proper lighting is one of the most important factors for Chaeto growth. It thrives under high-intensity, full-spectrum lighting. LED refugium lights designed for macroalgae are the best option, as they provide the right balance of intensity and efficiency. For optimal results, Chaeto should receive 12-16 hours of light per day. Too little light can stunt growth, while excessive light exposure may encourage nuisance algae. We typically recommend running your refugium lights opposite of the main display tank lighting to help reduce the overall pH swing of the system during the nighttime hours.

Refugium Lighting over Chaetomorpha

Water Flow

Chaeto benefits from moderate to strong water movement, which helps prevent detritus buildup and promotes even growth.

Nutrient Levels

While Chaeto helps reduce excess nutrients, it still requires some nitrates and phosphates to thrive. If nutrient levels are too low, Chaeto growth may slow or even stop altogether.

Nitrates: above 5 ppm
Phosphates: above 0.03 ppm

If Chaeto appears to be struggling despite proper lighting and flow, testing nutrient levels can provide valuable insights. In ultra-low nutrient systems, supplementing with a small amount of nitrate or phosphate may be necessary to maintain growth.

Maintenance Tips

Regular maintenance is key to keeping Chaeto healthy and maximizing its benefits in the aquarium. One of the most important tasks is harvesting. As Chaeto grows, it can become too dense, restricting light penetration and limiting nutrient uptake. Trimming back a portion of the algae every few weeks encourages continued growth while physically removing bound nutrients from the system. It’s best to remove small amounts at a time rather than all at once.

Another essential maintenance task is preventing detritus buildup. Because Chaeto forms dense mats, it can trap debris, uneaten food, and waste, leading to decay and potential nutrient spikes. To avoid this, gently agitate the Chaeto during water changes to dislodge and remove trapped particles.

Finally, monitoring Chaeto health ensures any potential issues are caught early. Healthy Chaeto is bright green, firm, and maintains steady growth. If it starts turning brown, becomes slimy, or breaks apart, it may be a sign of poor water quality, insufficient lighting, or nutrient imbalances. Testing water parameters and adjusting light and flow can help correct these issues.

Healthy Chaetomorpha

Troubleshooting Common Issues

Even with seemingly ideal conditions, Chaeto can sometimes struggle to grow or begin to deteriorate. Some common issues include:

Chaeto not growing: If growth has stalled, check lighting intensity and duration, as well as nutrient levels. Too little light or ultra-low nutrients can slow growth.
Turning brown or melting: This is often a sign of poor water quality or a lack of nutrients. Test your water while also ensuring proper flow. Remove any decaying sections.
Turning white: If your Chaeto is turning white, particularly near the water surface, this can be an indication that the light intensity is too high.
Competing algae in the refugium: Hair algae is a common competitor that will overrun Chaeto and should be removed manually.