coral dip

A blog on coral rehabilitation is quite useless without a discussion on basic coral evaluation; a proper coral inspection, dip, and quarantine procedure deserves recognition. While there are many differing views on how and what to quarantine, this is my approach. If it seems a bit neurotic and obsessive, well, that’s because I’m taking in some of the most sick corals in the hobby. Hopefully learning from the worst case can help for the best. Find what works for you, and stick with it.

The Preparation:

Before bringing home dying coral, I have an established reef aquarium that I keep running continuously with no fish (this helps prevent Cryptocaryon irritans infestations or other outbreaks in my aquariums). Contrary to popular belief, long-term survivability of a reef tank without fish is quite easy (I’m measuring success in terms of years without fish). Lighting must also be adequate for what you intend to keep. A good skimmer should not be overlooked as well. If the tank will be a hospital tank, then a carbon reactor is essential to help remove coral mucus. Basically, this aquarium system does not have to be fancy or have all the frills. It just has to work. I’ve had many different quarantine setups over the years, and the best were always the ones that were the easiest to maintain. Honestly, most of my quarantine tanks just received the “hand-me-downs” from my other tanks. The coral rehabilitation system fish room shown was circa 2012.

The Acquisition:

I obtain my corals from everywhere, but I only recommend purchasing them from reputable vendors/hobbyists. Each of my coral acquisitions is worked out individually with the owner (e.g., sometimes I pay, trade, or make other arrangements) on a case-by-case basis. Regardless of the source, I inspect every coral visually for pests, nuisance algae, or hitchhikers prior to purchase to assess probability of survival. Depending on the coral species, I may look for pest-specific parasites (e.g., Acropora-eating flatworm bite marks (AEFW), red bugs on Acropora, Montipora-eating nudibranchs). Once the coral arrives home I acclimate it into the quarantine tank.

Coral Dips and Inspections:

Acclimation:

Acclimations are short (approximately 15 minutes for temperature adjustment), unless I have a specific reason for a prolonged drip. These corals are often damaged through poor water conditions in their previous home, so it is typically best to remove them from the cause as quickly as safely possible. If they were damaged from other causes (e.g., high light, stinging), then a short acclimation is not as important. After the coral is acclimated, I open the bag and put the coral in one cup of tank water in a separate container. For this part, I absolutely love my Magnetic Stirrer Coral Dip Station and my DIY face shield.

Coral Inspection and Diagnosis:

At this point, I perform a more thorough inspection to provide me with a usable “diagnosis” (again, I’m not a medical professional, but having an idea of what is wrong is still critical.) This “diagnosis” helps me determine how to treat the coral. For example, if the coral is bleached, I try to look for other markers to determine why (e.g., high light, extremely low light, poor water quality, disease), so I can arrange the most appropriate treatment (e.g., correct husbandry, additional feedings, disease treatment). The flowchart below depicts my typical “triage,” where I try to determine the most appropriate reaction as quickly as possible. This process helps when I bring home a cooler full of dying corals; I have to prioritize treatments and move fast.

The coral is then removed from the plug/base, and all dead skeleton is removed as much as possible. I find this especially critical for rescue corals. In my experience, corals have an easier time growing new skeleton rather than growing over old, especially if the old skeleton has sharp edges. If the coral was placed in strong current, the coral’s tissue could catch on a sharp edge of its old skeleton and rip. In cases where removing all excess rock/ skeleton would harm the coral further (example below – the coral’s tissue was not stable enough to cut the skeleton with a band saw), I just trim down any sharp points.

Coral Dips:

Hydrogen Peroxide Coral Dip:

First, all LPS coral receive a dip in a mixture of hydrogen peroxide and tank water. This helps kill off some nuisance algae and some pests. Hydrogen peroxide isn’t great for the coral tissue itself (prevents calcification), but it isn’t immediate death either. I just use the normal 3% pharmacy-grade type, as the high-strength hydrogen peroxide is very dangerous (can cause blindness in humans). The ratio I use depends on the coral’s condition, but a 10:1 tank water:hydrogen peroxide (3%) is fairly safe on LPS corals for about 20 seconds. In severe cases, I go up to 4:1 for 60 seconds, but I rarely recommend this.

CoralRx, Iodine, and Other Dips:

Second, all corals except smooth-skinned Acropora (they die frequently) are treated with one milliliter of CoralRx mixed with the one cup of tank water (or scaled to the size of the coral). Smooth-skinned Acropora are instead treated with Lugol’s Iodine mixed to manufacturer’s instructions. There are other suitable coral dips, but CoralRx is what I prefer (no real reason – it works, and I haven’t found a reason to switch).

The small amount of water volume limits where pests can hide after the dip draws them out. While the coral is sitting in the dip, I use a pipette to gently baste the coral to blow any remaining pests out of the crevices. I also use a magnifying glass to identify the hitchhikers.

If I find any pests or evidence of them (bite marks or eggs, like this Acropora coral with AEFW), then I will do an additional pest-specific treatment. I keep all treatment medications on hand so I never find myself looking for drugs at an odd hour (hmm…that sounds bad…).

After dip time is completed, the corals are rinsed with quarantine aquarium water (NOT the bag water.)

Final Coral Preparation:

After the peroxide dip, if there is any ripped or cut tissue, I place a small amount of superglue gel along the line (as shown on the Fungia coral). This helps prevent water flow from literally ripping the tissue off the coral. Superglue gel reacts with water to form a type of plastic mesh. However, this reaction is exothermic, which means it releases heat. This can cause cell death, so extreme care should be used. That’s why I prefer wound-grade superglue gel, like Liquid Skin or Vetbond (this is pricey, especially considering when I get my regular superglue gel from the dollar store, but the medical type is worth it in these cases). I also seal any remaining skeleton or base rock in regular super glue. This way, if there are any remaining pests or algae spores, they will have a hard time getting past the glue barrier. The coral will quickly grow over the super glue, and within about a month the super glue should not be noticeable.

Coral Quarantine Tank:

Corals are then transferred to the quarantine tank where they will stay for at least 30 days. During that time I visually inspect each coral about every three days for pests/bite marks/and overall health.

During this time, it is essential to keep hermit crabs, cleaner shrimp, and the like away from the coral. These critters will go after the dying tissue and often take away healthy tissue in the process, which can quickly lead to the coral’s demise. It is especially essential to keep them away during feeding, as the process of stealing food from a coral’s mouth can be extremely damaging.

Lighting and flow should be kept low to allow the coral to acclimate. However, the flow rate must be high enough to keep the coral mucus from building up on the coral.

Coral Grow-out Tank:

After the 30 days, I go through the entire dipping process again. Also, if the corals weren’t stable enough to have the excess skeleton/ base cut, I do that at this point. The corals then go into a grow-out tank/secondary quarantine where they live for another 30 days. After those 30 days, I repeat the dipping process a third time. But, I leave the entire base of the coral or a nice fragment of the coral in the grow-out tank. This allows me to have a healthy backup in case I lose my main colony. The main colony is moved to the main display after the dipping process or fragmented for sharing.

Coral Inspection, Dips, and Quarantine Conclusion:

Yes, it takes a whopping 60 days for a coral to make it to my main display. But, through a proper process of coral inspections, dips, and quarantine, I can rest assured that I minimize pests and nuisance algae. I will not have to rip out my corals to treat for AEFW or go almost two years without Montipora corals to treat for Monti-eating Nudibranchs. “An ounce of prevention is worth a pound of cure.” I can also sell my coral clippings knowing I’m providing a very healthy specimen to another hobbyist.

No matter where you buy a coral from, always quarantine. Do not trust anyone, even me. Everyone makes mistakes, and sometimes even a backup safety fails. You do not have to quarantine like I do, but any amount is better than nothing. I hope this post provides some insight on how to improve your procedures.