Corals have a pretty tough life on a coral reef; the constant battle with changing water conditions and human stressors. Luckily for hobbyists like yourself, leather corals are easy to keep in aquariums because you can control the conditions.
However, sometimes things can go wrong, and one issue is when leather corals start turning white.
Why Is My Leather Coral Turning white?
When you think of coral turning white, often you will jump to the conclusion that it’s bleaching because of the media and how the Great Barrier Reef turned ghostly white because of coral bleaching. However, this is not always the case…
1. Shedding
When your leather coral sheds its skin coat, it can look like it is bleaching. During the shedding process, corals often close their polyps, giving them a paler color than usual, and sometimes they will turn white. This is because your leather coral is using a lot of energy to complete the shedding process.
If your leather coral is shedding, allow it time to do so, and ensure it is getting enough nutrition, either via lighting or with additional feeding.
2. Stress
Stress happens to everyone, even your leather coral, and this starts with its journey to your home. Transportation can be a very stressful time for your leather coral, and occasionally, some corals do not survive the journey.
If you have removed your leather coral from its packaging and noticed that it is completely white, call up the local fish store (LFS) or the person you bought it from, as you may be able to get a refund or a new one sent to you.
Another stressor leather corals experience is acclimation. When your leather coral arrives, you should dip it in a coral-safe dip to remove any pests, particularly predatory Nudibranchs, like Tritoniopsis elegans, which are known to munch on soft corals like your leather!
When you are ready to add your leather coral into your aquarium, place it near the bottom and slowly move it up to its final destination. This gives your coral time to acclimate to its new home, which can take a month or two.
3. Swings In The Water Parameters
If your aquarium has experienced large fluctuations, particularly in salinity, alkalinity, and temperature, it can make your leather coral turn white.
Ideal water parameters for leather corals:
- Temperature: 76-82°F
- pH: 8.0-8.4
- Salinity: 1.025
- Calcium: 350-450 PPM
- Magnesium: 1250-1350 PPM
- Nitrates: <10 PPM
- Phosphates: <0.10 PPM
It is important to keep on top of your water changes using RO (reverse osmosis) water, and dosing your aquarium water where needed.
4. Tissue Necrosis
Take a close look at your leather coral. Do you notice algae growth on top of the white areas? Algae grow on unhealthy, dying tissue, so, if this is the case, your leather coral is likely suffering from necrosis.
There are two kinds of tissue necrosis depending on the speed of the infection: slow tissue necrosis (STN) and rapid tissue necrosis (RTN). If your leather coral starts to become necrotic and starts melting, tissue necrosis is already underway!
Tissue necrosis can be from any of the following:
- Poor tank conditions
- Lack of trace elements
- Heavy sedimentation
- Improper lighting
- The presence of a toxin
- Pests and/or fish damaging your leather coral’s tissues
If you suspect your leather coral has STN or RTN, then you must test the water immediately and check that the parameters are within range. If the necrosis is severe, consider removing your infected leather coral, as it can be contagious to neighboring corals.
The good news is that necrotic areas can easily be trimmed off using a sharp blade. Carefully cut into the healthy flesh of the coral above or below the infected areas, and discard the tissue. Do a quick coral dip and siphon aquarium water around the cut area to check you haven’t missed anything.
Most leather corals will recover from tissue necrosis if tank stability is maintained, however, sit tight, as your leather coral may take months or even a year to fully recover.
5. Coral Bleaching
Coral bleaching is something you are probably very familiar with. Because of global climate change, mass coral bleaching events have happened in the wild due to elevated sea temperatures and sunlight overexposure.
If your aquarium temperature is too high, your leather coral will expel the zooxanthellae from its tissues, turning ghostly white. Do not fear yet, as bleached corals are not dead corals (yet). Most corals can survive bleaching events, and luckily in aquariums like yours, you can easily change the environmental conditions to help them recover.
If bleaching is the reason your leather coral is turning white, first, turn down the lighting very slowly. Any changes must be done steadily to reduce stress levels for your coral.
Leather corals thrive under low to moderate lighting, with a PAR range between 50 and 150. However, some leather corals can tolerate higher PAR levels, so always check which leather species you have from the supplier. You want to hit your leather coral’s sweet spot without bleaching it!
Can Bleached Leather Corals Recover?
To dive straight in, yes, leather corals can recover if there are zooxanthellae still present inside your leather coral’s tissues.
Recovery of your bleached leather coral depends on the water conditions following the bleaching process, and how severely affected your coral is. As long as you can create a stable environment again, your leather coral should fully recover.
However, be patient, as this can take some time – time is usually the only indication and “cure” to bleached corals.
Is Your Leather Coral Dying?
When your leather coral faces stressful situations inside your aquarium and you are too late to act, your leather coral may start dying. As you already know, leather corals have epic colorations and shapes, so, if your leather coral is looking a little worse for wear, then it may be the early signs it is starting to die.
Your leather coral’s polyps should look nice and fluffy. As leather corals start to die, they deflate their polyps causing body-shape deformation, which can lead to death.
In addition to deflation, your coral’s polyps may also exhibit holes or areas missing, which allows algae to grow and reproduce. This will rot your leather coral’s flesh turning it black, eventually causing your leather coral to shrivel up and detach from its base.
How Do You Preserve Leather Coral?
Leather corals are easy to care for and are fairly durable, however, a well-maintained aquarium is critical for them to thrive. To help you out, here is a quick summary of your leather coral’s needs!
- Lighting: Low to medium (PAR 50-150) – blue and actinic spectrum lighting is best for color and growth
- Flow: Moderate to high, turbulent/non-linear
- Placement: Middle third of the aquarium
- Water chemistry: See above under “Ideal water parameters for leather corals”
Conclusion
If your leather coral starts turning white, it is an indication something inside your aquarium is not quite right.
Leather corals are fairly durable, so if you maintain a stable environment and give them some time, soon your leather coral will be thriving again!
