Is Coralline Algae Good? Helpful Information and Tips for Saltwater Tank Hobbyists.
What’s your ultimate reef tank goal? While you may hold unique desires, vibrant color and solid covering is the shared goal by most aquarists.
The quest to accomplish this goal is what began my journey into the world of algae. Unlike popular belief, not all algae is bad. In fact, there’s one species that’s actually necessary for the health and vitality of your underwater world.
Author:
As a lifelong aquarist, Yuliya has an endless curiosity about our underwater universe. After graduating with a bachelor’s in Environmental Engineering, she transformed her passion into a successful career. While working at the Institute of Environmental Protection in Moscow, her passion for saltwater and reef aquariums only increased. Moving to the United States in 2013, Yuliya embarked on another impactful journey by sharing her unprecedented experience for all aquarium hobbyists ... Read More.
Coralline algae acts as a food source, structural support system and environmental protector for saltwater, and even freshwater, reef systems. It’s no surprise growing coralline algae is the primary goal for so many marine aquarists.
Obviously, if nature relies on this algae to develop healthy and vibrant marine ecosystems, so does your aquarium. But what exactly is this essential algae? Moreover, how does it make its way from the ocean into your living room?
The Ancient Underwater Rose - What Is Coralline Algae?
Let’s start at the beginning. Coralline algae is a red algae subtype belonging to the Corallinales scientific order, which belongs to the Rhodophyta division. Okay, now that’s out of the way, let’s actually dive into the depths of this invaluable algae.
As you’ve maybe noticed, coralline algae grows in two distinct patterns:
- Branched, tree-like formation that appear to be reaching out into the open waters. Some look like tiny castle spires in closely grouped configurations.
- Spread out crusts covering the surfaces of rocks, shells, sea grass or coral skeleton.
But what you may not know is its growth pattern is determined by its classification. With anywhere from 6,500 to 10,000 red algae species, it’s no surprise coralline algae has multiple classifications. Let’s take a moment and explore its two primary groups:
- Geniculate Coralline Algae - Also called articulated algae, this coralline grouping is what I described in the first growth pattern listed above. It attaches itself to rocks, reefs and other substrates through a root-like appendage known as a crustose. Its visually dynamic appearance is due to its tree-like growth pattern, which looks like tiny underwater trees. Calcified sections are connected by non-calcified segments, which provides flexibility against strong ocean currents.
- Non-geniculate Coralline Algae - Also called non-articulated algae, grows in a sheet, or covering, pattern. Because of this, it’s often referred to as encrusting coralline as it forms a calcified crust over the surface of coral skeletons, sea grass and rocks. Its thickness ranges from a couple of microns to several centimeters. Non-geniculate corallines grow in compact sections to massive, nodular crusts. Interestingly, this grouping can also be free-living, which means it floats throughout the ocean unattached to reefs, shells or other substrates.
[ ! ] Don't confuse with Red Slime Algae !
Regardless of classification, its internal structure is not only universal across all types, but also strikingly familiar. Under a microscope, crustose coralline algae is a massive collection of honeycomb-shaped compartments. This ingenious design provides maximum support as it grows, which is only 0.4 to 1.2.-inches per year.
What surprised me most about coralline algae is its cellular structure. Limestone covers cell walls and as it grows, these sturdy cells stack on each other. Over time, as it thickens, coral reef foundations become stronger. This is why coralline algae is the primary reef builder in areas with strong, rough currents.
And we don’t stop there.
Coralline Algae and Your Tank - What You Need To Know.
So you want to take your saltwater aquarium to the next level? Even if you’ve never operated a reef tank before, establishing and maintaining coralline algae is surprisingly easy.
The cheapest and easiest way to add coralline algae into your tank is to introduce a live rock, or anything else that’s encrusted with the algae, including snails! While many believe snails will eat and destroy coralline algae, the vast majority of reef aquarium snails species aren’t typically interested in having coralline for dinner. In fact, the additional of snails can boost reef tank fauna.
While adding coralline into your tank is a breeze, there’s more to cultivating healthy growth. Don’t worry, if you follow the three pillars of growing coralline you’ll do just fine!
Pillar #1 - Lighting Fundamentals.
The root of healthy growth comes down to lighting. While lighting preferences vary based on algae type and the tank environment, there’s a couple of rules to keep in mind when establishing a coralline colony:
- The Best Lighting…Maybe? - There’s no such thing as a lighting solution that’s best for every coralline algae. It seems every algae has its own unique preferences. But what I’ve found is the vast majority of coralline algae grows well when 10,000K and Actinic Blue lights are used at an intensity of 1.6 watts per tank gallon. My advice? Continually adjust lighting to satisfy your coralline. Be patient and observant!
- Natural Light Cycles - Maximize growth potential with light cycles that mimic sunlight durations.
Because coralline algae is photosensitive, excess exposure to light can result in light shock, which turns damaged portions white. However, not all white spots are caused by light shock. Astrea starfish eat the film along the surface of coralline, which bleaches the damaged areas.
Pillar #2 - Stable Tank Parameters.
Aquatic life, including coralline algae, thrive when water parameters remain relatively stable at all times. This typically requires regular water testing and more frequent, smaller water changes. Prevent shocking your tank by avoiding large water changes.
As a general rule of thumb, aim for the following water chemistry parameters:
- Calcium - 350 to 480 ppm
- Alkalinity - 2.8 to 4.3 meq/L or 7 to 12 DKH
- pH - 7.9 to 8.3
- Magnesium - 1300 to 1380 ppm
- Phosphates - Less than 0.25 ppm
- Nitrates - Less than 5 ppm
- Temperature - 78 to 80 degrees Fahrenheit
Pillar #3 - Growth Supplements.
Even when tank parameters are ideal, sometimes a boost is necessary to kickstart algae development. After experimenting with quite a few coralline growth supplements, all were pretty much useless except for an ingenious product my fellow hobbyists suggests - PurpleUp.
After using PurpleUp, I was thoroughly convinced. In short, PurpleUp is a growth accelerator. Basically, it’s like Miracle Grow for algae.
It works by injecting nutrients directly to coralline without promoting nuisance algae growth. Through my research, I found it’s the quality and quantity of ionic calcium, magnesium, strontium and carbonate that promotes such rapid, and healthy, growth.
Although there’s no such thing as a magical supplement to grow coralline overnight, out of all growth supplements on the market, this is the one I trust in my own tanks to kickstart algae development, but if you don't want to spend money, skip it. I'm sure you'll get success anyway. Please share in comments if you had good experience with other products in this category!
Now the best part !
Enhance Your Tank - What Coralline Algae Looks Like.
In my opinion, some of the most breathtaking saltwater tanks are bursting with natural color. There’s nothing quite as dynamic as natural coralline algae. The look of natural live rocks !
You may think this algae only produces a pinkish hue. Sure, purple this is the dominant coloration, but just because it belongs to the red algae scientific order doesn’t mean it’s only this color. In fact, coralline algae comes in a variety of colors, such as white, purple and green. Its vibrant coloration comes from specialized pigments known as phycobiliproteins.
With over 1,600 discovered species, it’s impossible to definitively, or at least quickly, describe all the variations of coralline algae design. Along with the aforementioned colors, you can find species with lavender, magenta, violet, yellow and even orange coloration. It’s no wonder they’re so popular among novice and experienced hobbyists.
The Interesting Realm of Algae - Fun Facts.
You thought its ability to sustain coral reefs was interesting? Just wait till you read some of these lesser-known facts:
- Without coralline algae marine species, such as mollusks, parrot fish and sea urchins wouldn’t exist in such concentrations.
- Coralline algae is the cement binding reefs together and preventing damage from strong ocean currents or waves.
- Modern dental bone implants use coralline algae, and its cells are used to assist bone tissue regeneration.
- Limestone, in part, comes from coralline algae cells, which are lined with this material.
- Certain species shed their outer layer to prevent seaweed from overtaking it and the coral reef.
- While primarily found in saltwater, there is one species of coralline algae capable of growing in freshwater systems.
- Fossil records dating back to the Early Cretaceous period showcase both types of coralline algae.
But that’s just part of the story.
The Importance of Coralline Algae in Saltwater Aquariums.
While the importance of this algae is almost limitless, let’s take a look at the three overarching benefits coralline algae for aquariums:
Strengthens and Stabilizes Reefs and Rocks.
Aquarium reefs are notoriously easy to accidentally shift. Coralline algae cements reefs and rocks together. It’s basically glue designed to prevent reefs from dislodging during routine maintenance or an unexpected aquarium accident.
Prevents and Combats Nuisance Algae.
Coralline algae doesn’t like other algae roommates. In my experience, maintaining healthy coralline algae growth significantly reduces undesirable algae, such as green algae, mat algae, diatoms and hair algae. As it grows and encrusts the surface of reefs and rocks, it covers areas where undesirable algae likes to grow.
In-Tank Chemical Defense System.
Think coralline algae inhibits nuisance algae simply because it’s epiphytic, or is a plant that grows on another plant without causing harm? Think again!
A vast majority of coralline species release various chemicals that literally fight off other forms of algae. Talk about beneficial!
Even better !
In-Depth Look At Coralline Algae - Questions and Answers.
Let’s take a look at some of the most common questions I’m asked about coralline algae:
- Where does it grow? - In the wild, coralline algae lives in a variety of intertidal settings and in depths of water up to 270 meters, which is the deepest light can penetrate. Typically, all coral reefs are home to this beautiful organism. In aquariums, coralline thrives in nutrient-rich water with appropriate lighting and frequent water changes.
- Why does it grow? - Like all living organisms, growth occurs as a result of proper nutrients and optimal surroundings. In evolutionary terms, its growth ensures coral reef longevity, preventing coastal erosion along coastlines, safe breeding grounds for herbivorous invertebrates and preventing the overpopulation of invasive organisms, such as seaweed.
- How does it reproduce? - Coralline algae reproduction is somewhat complicated as it spreads through asexual and sexual means. Asexual reproduction, or spreading, occurs when spores and cellular fragmentation flake off the main organism. Sexual reproduction is pretty complex, so basically male algae releases gametes known as spermatia. Guided by currents, the spermatia enters the carpogonial branch of female algae and creates carpospores that transform into tetrasporophytes and are released into the water.
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I know, this was a lot of information to digest. Learning the intricacies of saltwater and reef aquariums isn’t a quick or easy task. However, you don’t have to go at this alone. Register at Reef2Reef and join an amazing community of people ready to help you and answer to your questions.
by Yuliya Ivanova for ReefHacks.
Article Photography by ReefHacks / NASA / Derek Keats / Jean Kenyon / Kyle Taylor - CC BY 2.0 License