If you have a reef tank, and you are looking for some fast growing corals, there are a lot of great choices. This list will be mostly soft corals and some SPS corals. Of those, softies seem to be the fastest growers. They can overtake your aquarium if you do not watch them carefully.
Growing can be classified as a single coral getting bigger or growing new pieces. For example, a Bird’s Nest coral will get a lot bigger in size. On the other hand, Discosoma mushroom corals will not keep getting larger. But, they will grow by dropping new baby corals near them.
Some of these can be problematic because they can be like weeds in your reef tank. Most notably, Anthelia, Green Star Polyps, and Xenia. On the flip side, these are low cost corals that can cover wide areas of your tank and quickly. If that is what you are going for, then there are several options.
Depending on what you are looking for in your tank, fast growing corals can be a good thing or a bad thing.
8 Of The Fastest Growing Corals For Your Reef Tank
Anthelia (Anthelia sp.) or Waving Hand corals are some of the fastest growing corals in marine tanks. These are also called Glove Polyp corals.
These are soft corals that are similar in appearance to Xenia. Their polyps are much larger, and they have longer stalks. They also do not pulse like a Xenia can.
They come in many colors including pink, tan, brown, and blue. These are popular for beginners because they grow rapidly, and they can tolerate a wide range of water parameters.
Anthelia spread quickly by growing their mat out at its base. It will spread over live rocks, and if any rock is adjacent, it will spread there too. If you have ideal tank parameters, Anthelia can take over your live rock.
Xenia or Pulsing Xenia is a soft coral that you either love or hate. Some reefers love the pulsing nature of the polyps, and they can provide movement to your tank. Other reef tank owners consider it to be an invasive weed underwater.
These soft corals do great in tanks with higher nutrients, and they will grow quickly. You can limit their growth (sometimes) in very low nutrient tanks.
These corals spread out and will cover anything that its base touches. If you have it on a rock, it will cover the entire rock in time. If you have Xenia on a live rock with other corals, it can overgrow that rock. It will also move from rock to rock. This is why it is referred to as an invasive coral.
The best way to enjoy Pulsing Xenia is to put it on an isolated rock with the expectation that it will completely cover it. This way, it will not spread throughout your tank. You can enjoy this coral and the beautiful pulsing nature without worrying about it taking over.
3. Green Star Polyps
Green Star Polyps or GSP coral is very similar to Xenia in how it spreads. It is a bit easier to manage on sand and glass though. It has a purple mat where its green polyps will grow out of. This can be easily cut or fragged with a sharp blade.
Like the Xenia, you can manage it as long as you have an idea how to use it in your tank. Many reef tank owners will use it to cover the back glass in their aquarium. This way, its quick growth can be used to your advantage. You can form a green carpet of polyps on your glass, sand bed, or overflow. This can provide a beautiful swaying motion of green polyps flowing in the water.
If you place it in the middle of your tank on some live rock, it will spread over everything. The purple mat is difficult to remove from live rock. Isolation and plan is the key to enjoying this fast growing soft coral.
4. Kenya Tree Coral
Kenya Tree is a fast growing soft coral because it can drop little baby Kenya Trees all over your tank. These corals self-propagate by dropping little stems. These buds will attach to substrate or live rock, and a new colony will form.
If you do not actively manage them in your aquarium, then new colonies will continue to sprout up everywhere.
5. Discosoma Mushroom Corals
Mushroom corals can grow quickly in a tank by leaving a piece of their foot behind as they travel. This “foot” will sprout into a new mushroom coral. As it gets bigger, it will start to move and leave babies behind as well. As more and more new corals grow, there will be a lot of new mushroom corals sprout up.
These are great for beginners because they are super hardy, and they do not require expensive lighting for growth. They can also cover a large area on your live rock quickly because how fast they multiply.
Under the right conditions, a 2 mushroom frag can drop 3 new baby mushrooms in a month. So, one frag can grow from 2 to 5 in just 30 days.
Mushroom corals like low light and low flow. They do tend to drop more baby mushrooms with higher light. This is probably due to more energy they receive from light which allows them to move and leave a piece behind.
Zoanthids or Zoas, are one of the most popular type of soft coral in the hobby. These corals can be purchased per polyp, and most frags usually have around 3-5 heads on it. There are so many different varieties. Under right tank conditions, these corals will develop new heads, and they will cover a frag plug quickly. For some varieties, it is not unusual to see multiple new polyps each month. Over time, they can spread over live rock.
While some of them can grow quickly, they will not overtake your aquarium like Xenia or GSP.
You will need to keep some nutrients in your tank for fast growing. These corals do not grow well in low nutrient tanks. A good target for growth would be 5-7 ppm of Nitrates and 0.03 to 0.05 Phosphate. It will be difficult for them to spread if you run a ultra low nutrient tank.
Montipora is one of the fastest growing SPS corals out there. This includes Plating Montipora (Montipora capricornis) and Branching Montipora (Montipora stellata ). This branching coral will spread quickly, but it can be cut back if needed.
These are a great choice for starting out with SPS corals. They are inexpensive, come in a lot of different colors, and they will grow fast.
Certain ones like Orange plating montis have an incredible growth rate.
8. Bird’s Nest Coral
The Bird’s Nest Coral (Seriatopora hystrix) is one of the easiesty SPS corals to grow. They should not be added to your tank if you are a beginner though. These corals can grow into a big “nest” from a single frag. In the right conditions, this can happen quickly.
This SPS coral will need bright light to grow fast. While this coral is on the list, you need to remember that growth rate of an SPS is not close to that of soft coral like GSP and Xenia. Nobody will refer to a bird’s nest coral as overtaking their tank. This is also one coral that needs really good water parameters to see the best results.