HOW TO CARE FOR YOUR LEPTOSERIS CORAL

Leptoseris Coral Care

Leptoseris corals are a small polyp stony coral that is a relative newcomer in the reef aquarium market. The common name for Leptoseris is wrinkle coral but just about everyone in the hobby refers to this coral by its scientific name rather than its common name.

When Leptoseris first arrived there were only a few color variants and at that time, Leptoseris were very expensive. Luckily, Leptoseris are one of the fastest growing corals. Stores and hobbyists propagated them extensively thus increasing both the supply and varieties for sale. The number of varieties was key because Leptoseris are not frequently imported compared to other stony corals. Due to sustained aquaculture efforts, the uncommon color morphs that were imported became readily available.

The first Leptoseris corals introduced had some variant of orange coloration. Some were solid orange, while others had an orange body with highlights around the mouths. Over the past several years, more color morphs made their way into the market place. Our favorites here are a bright yellow variant known as a 24K Leptoseris. It will be interesting to see if there are more color morphs that will turn up in the future.

One attractive aspect of their appearance is their fluorescence. Not every coral is loaded with fluorescent proteins so they may have a pleasant color under daylight lighting but they do not glow under actinic lighting, so they will appear drab. Leptoseris however have some of the most intense fluorescence. This is great because some of the colors are uncommon to find fluorescence in such as the yellows, oranges, and reds. In addition to their exotic color palate, Leptoseris have a subtle pinstripe pattern that gives them an almost metallic appearance when viewed from afar. When they grow out, the coral encrusts over the surface of the rock and can make for a bright and beautiful landscape.






Location

Leptoseris are found all over the tropical waters of the Pacific. In particular, they are regularly harvested from the islands of the Indo-Pacific including Fiji, Tonga, Solomon Islands, and the Great Barrier Reef.



Lighting

We have kept Leptoseris in different lighting intensities here at Tidal Gardens. The best results as far as growth and coloration are concerned were achieved under moderate lighting intensities, between 75-125 PAR. Leptoseris are fairly adaptable to different lighting so dialing in an exact light is not something I would spend a lot of time doing, but long term lighting that is too dim might dull their color and lighting that is too bright risks burning the coral.

If you start to see the coral starting to turn lighter and bleach out, the most likely culprit is inappropriately high lighting intensity however there may be other causes that we will discuss later. When in doubt, favor lower lighting intensities until it is clear that the coral is demanding more. The lowest lighting we have grown this coral in was around 40 PAR. It grows fine in those conditions, but the appearance is not as dazzling as colonies that are grown in higher light.

Leptoseris do not shift colors though. Even under suboptimal lighting they maintain consistent color so there is no risk of a bright orange colony suddenly turning a dusky green.

As far as lighting spectrum, my favorite blend is roughly a 12,000K light so if you can imagine a blend of ATI blue plus and coral plus T5 bulbs that is what I shoot for. That is my go-to favorite, but Leptoseris’ amazing fluorescence is one of the major selling points so I also like to give it plenty of time under just actinic lighting for viewing purposes.

Low Light

Low light translates to about 30-50 PAR

Medium Light

Medium Light is between 50-150 PAR

High Light

High Light is anything over 150 PAR

Lighting is a loaded topic, so for a more in-depth discussion of lighting, please check out our Blog all about Lighting or see our detailed lighting video below.




Water Flow

Leptoseris appreciate low to medium flow. There are two things that I am looking to accomplish with flow for this coral. The first is to give it enough flow to keep it clean. Although Leptoseris is an encrusting coral, they can develop irregular folds and bowl-like shapes that can trap detritus if not given enough water movement. Detritus build-up will cause the coral to die back where it collects. Providing elevated flow levels prevent this accumulation.

There is such a thing as too much flow for this coral. If you have a powerhead blowing right at Leptoseris from short range, it may kill off some of the tissue at that point of contact. What I look for is just a little bit of inflation and extension. That may sound non-intuitive talking about inflation in a small polyp encrusting coral, but a healthy and happy Leptoseris can swell slightly, especially towards the edge of the colony. It is a very subtle thing I look for and the opposite appearance is a warning sign that something is wrong. I don’t like seeing Leptoseris drawn in tight.

Remember to pay attention to maintaining consistency of water movement as time goes on. Unfortunately, this is a moving target.

There are two things over time that dramatically affect the performance of water flow systems. The first is the growth of the colony itself. Successfully growing corals comes with the downside of the corals cutting down the flow significantly. As colonies get larger and larger, it is important as hobbyists to pay close attention to changing flow demands and consider adding more flow or pruning colonies back to allow more space for water to flow through.

Secondly, other organisms such as algae, sponges, and other sessile invertebrates love to grow in and around the aquarium’s pumps and plumbing. For this reason I recommend taking apart pumps and powerheads regularly for servicing. It does not take very much growth or blockages to greatly limit water flow output.

Providing periodic low flow is also beneficial for this coral for the purposes of feeding. Spot feeding Leptoseris is not something that a lot of hobbyists do, but I am all for it if people want to be proactive. They are not a particularly aggressive feeder, and if the colony only receives strong flow it won’t get a good opportunity to capture food.



Feeding

Leptoseris are photosynthetic so they will get the majority of their nutrition from the lighting provided. This next discussion is for hobbyists that want to proactively feed their corals.

Leptoseris do not put on dramatic feeding displays like some large polyp stony corals. To see any kind of feeding behavior you practically need a macro lens and run a time lapse. When corals like Leptoseris take a long time to ingest food it makes it more likely for other tank inhabitants to come steal the food away.

Despite not being the most aggressive feeders in the world, there are three great sources of food that work well for broadcast feeing. These three are amino acids, small zooplankton, and simply having fish present as a nitrogen source.





Starting with amino acids, they are simple organic compounds that play a major role in building proteins as well as other biological functions at the cellular level. There are a little over 20 different types of amino acids but in most animals, there are only 9 or so that their bodies cannot synthesize and must be taken in by feeding. Corals regularly take in available amino acids from the water column so it is easy to provide them with adequate quantities by broadcast feeding an amino acid solution. They are available from any number of commercially available reef supplement manufacturers. This may be the easiest way to feed Leptoseris because as long as amino acids are bioavailable in the water column, the corals will soak them up.

Next up, small zooplankton include organisms such as rotifers and cyclops plankton. There are two kinds, frozen and powdered. The frozen variety makes an orange cloud when thawed introduced into the tank. Sometimes rotifers are included in frozen blends or coral specific frozen foods. There are also powdered coral foods that contain zooplankton. The presence of rotifers in the water is immediately apparent to the corals because many of them will open up and initiate their feeding behavior. For what it is worth, I notice a more pronounced feeding behavior with the powder supplement than when feeding the frozen food alone.

Last point on nutrition, having fish in and around coral colonies tends to have a positive effect. Fish provide a steady dose of nitrogen and phosphorous which in small quantities is helpful for their nutritional needs.

Although coral nutrition is important, there is such a thing as too much of a good thing. Most of the nutrition Leptoseris needs will come from the lighting and they will be absorbing other nutrients from the water. If you are going to experiment with broadcast feeding or target feeding, start slowly with it and don’t expect explosive changes overnight. Having some phosphate and nitrate in the water is beneficial but overfeeding can cause these parameters to rise to dangerous levels that can be hard to remedy.


Water Cleanliness

Phosphate and Nitrate are great general measurements of water cleanliness however corals do need to have some present for their nutrition because those are compounds that they cannot get from photosynthesis alone. If Nitrate levels get too high corals may react negatively by taking on drab coloration or suddenly dying back. If Phosphate levels are too high, it may feed into an unwanted algae bloom.

There can be trouble as well if these two parameters are too low. Often I see Leptoseris struggle in systems that too aggressively implement carbon dosing or GFO. The corals first take on a shrunken emaciated look and then they start dying off. For Leptoseris specifically, I would rather see Nitrate and Phosphate levels on the high side than barely detectable because we have kept them in systems with very high nutrient with no difficulties.


Water Chemistry

Because Leptoseris are stony corals, and fast growing stony corals at that, there are three major chemical parameters that are needed to power that skeletal growth. These parameters are Calcium, Alkalinity, and Magnesium.

Starting first with Calcium… Calcium is one of the major ions in saltwater. In the ocean, its level hovers around 425 parts per million (ppm). As a coral grows calcium is absorbed from the water and used to forms its calcium carbonate skeleton.




Alkalinity on the other hand is not a particular ion, but rather a general figure of carbonate availability in the water. Technically it is the amount of acid required to lower the pH of saltwater to the point bicarbonate turns into carbonic acid. If you have more alkalinity, it can soak up more acid. Less alkalinity and you have less buffering capacity making the tank more susceptible to chemical changes.

In practice alkalinity tends to be the parameter that fluctuates the most, so if you cannot manage to test all three, Calcium, alkalinity, AND magnesium and had to choose just one test to perform, test for alkalinity. In the wild, the alkalinity of the water is around 8-9 dkh though some aquarists like to overload this parameter a little and keep their tanks around 10 or 11 dkh. There is some belief that having elevated calcium and alkalinity in the water contributes to faster stony coral growth.




One quick note about adjusting calcium and alkalinity: it can be a little tricky because of how they interact. For example, if your reef tank had a calcium level of 300ppm when you desire a value closer to 400ppm, you could theoretically add a calcium supplement to boost it. Unfortunately, reef aquarium chemistry is dynamic and solutions to chemistry issues are rarely that straightforward in practice. Addition of a calcium supplement in this manner often comes with a corresponding fall in alkalinity levels.

This see saw effect between calcium and alkalinity stems from how the two ions interact with one another. The two ions combine to form calcium carbonate and fall out of solution, thus lowering both levels.

If you are experiencing this in your systems, the possible culprit with calcium and alkalinity instability is Magnesium. It may seem counterintuitive that the solution to calcium and alkalinity imbalances is to elevate magnesium, but the three ions interact regularly.

So why Magnesium? Magnesium behaves chemically similar to calcium. It can bind up carbonate ions thus increasing the overall bioavailability of alkalinity compounds in the water. If you are tweaking calcium and alkalinity and getting strange results, you may want to make sure it is not your magnesium level that is low. In the ocean, Magnesium sits at about 1350 ppm.




That should give you a little bit of background on the chemical parameters to keep an eye on. Remember though that the growth rate of Leptoseris may make chemical stability more difficult to pin down, especially with large colonies. In general fast growing SPS soak up calcium, alkalinity, magnesium and trace elements at a much faster rate. At first just regular water changes may be sufficient to keep up with the chemistry demands of the corals, but as the biomass increases, you may have to work in supplementation such as kalkwasser, calcium reactors, or two part dosing… or some combination of the three.




Coral Aggression

Let’s move onto the topic of aggression. Leptoseris have to be given plenty of space because not only are they fast growing and can encroach on other corals, they send out sweeper tentacles. They are not hyper aggressive like Galaxea, but they have these little sweepers that can extend about an inch.

The video below provides an overview of the different manifestations of coral aggression and ideas on how to mitigate some of the risks inherent in keeping corals in small quarters.



Propagation

Once Leptoseris get going, they have an impressively fast growth rate. They are easy to break apart either by bone cutters or by band saw, however they can be a little tricky at times to glue down. We use dollar store gel super glue and just use extra when gluing them down.




Summary

So what kind of tank is Leptoseris best suited for? I see this coral being used as a ground cover in SPS dominated tanks as well as mixed reefs with other stony corals. It is a very fast growing coral and can quickly cover rock work basically acting as a much more exotic replacement for coralline algae. Alternatively, it can be used to cover custom made substrates whether that be interesting rock scapes to give it a branching look or sculptures even if the hobbyist is looking to add some novelty to the tank.

One interesting design choice I thought about was with a customer the other day. He wanted to make a coral tree-themed tank where the rock work had a thick central trunk that would extend out with Tonga branch rock and create a canopy. Leptoseris could make an interesting cover coral on the trunk part because it is fairly good in low light and there are enough color variations to provide either a muted color as to not distract from the limbs and leaves of the tree OR you could go the complete opposite direction and use a bright yellow Leptoseris to make the trunk look like it is made of gold. You could even go with a mix of different leptoseris colors to make a painted tree look.

That pretty much does it for Leptoseris. Hopefully you found this article helpful. Until next time, happy reefing!


Than Thein