Since 2 years have passed since this thread started, and a couple hundred more corals are healthy now instead of being live rock...I figured I should update my tips. Again, I'm no marine biologist or anything more than a hobbyist. But, this is my passion, and I hope others will at least take something from my experiences.
Below are my updated tips. My previous tips can be found on the first page of this thread.
First thing - selecting the coral:
My LFS know that I rescue corals and usually keeps me in mind when they get a damaged shipment. This includes boxes that got overheated during shipping, damaged corals during shipping, and sometimes "freebies" that wholesalers throw in since they know they can't sell them. Some other LFS purposely order "damaged" shipments. Get to know your LFS and keep an eye out!
For the actual coral itself, look for corals that have at least the majority of one mouth. I haven't had any luck rescuing corals with less than 3/4 of a mouth (unless they are my own frags). Usually rescue corals with less than 3/4 of a mouth have just gone through so much stress they won't survive. (If it's a freebie though, it's worth trying!!) Avoid corals with jelly-like substances on them. I also try to avoid obvious pest-damaged corals unless I know exactly how to treat it and have the medication on hand. Nothing worse than coming home to a pest you don't know how to treat and don't have the medication for!
Tank itself:
Of course, you want stable parameters, but this is really really important with rescue corals!! I actually acclimate the rescue corals less than healthy corals (float for ~15 min) since they are probably just getting their bag water really nasty.
Also, hermit crabs and other scavengers may go after the dead/decaying tissue on a rescue. In that effort, they may take healthy tissue along with it. Use caution - watch out for the scavengers! My QT and hospital systems do not have crabs at all - only snails.
Resources on hand:
If you're bringing home a pest-infected coral, make sure you have the knowledge on how to treat it, the medications, and the time. I keep a ready supply of superglue, scalpels, bone cutters, tweezers, you name it as well. The biggest increase in my rescuing success has been the addition of a band saw. This allows me to cut off tissue necrosis and a bit of the healthy flesh in order to decrease infection chances. I also have a microscope to positively ID pests. Please note that not all of this is required for success, but it significantly helps.
Dipping:
Many rescues are just dying from poor water quality...but there are plenty that are suffering from some disease, infection, injury, or pest. There are many good coral dips out there (Lugol's, CoralRx, etc). Personally, I use Bayer Insecticide (available at your local home improvement store in the United States) at the dosage of 0.5 ml per 2 cups tank water for 15 minutes (and then rinse the coral in fresh tank water to remove the treatment.) This seems to kill just about every pest with no problem to the coral. Make sure to follow the manufacturer's safety precautions - it's nasty stuff.
I also use a 10:1 tank water to drugstore grade hydrogen peroxide dip for about 20-30 seconds in order to kill off algae. This is a pretty nasty treatment...to everything. Use extreme caution for yourself and the coral - if the coral gets stressed, take it out and rinse it in new tank water before placing it in the aquarium.
Coral Prep:
Here's where I think is the MOST IMPORTANT!!! Use bone cutters (or preferably a saltwater band saw) to remove excess dead skeleton and necrotic tissue. New tissue growth seems to have more trouble covering old skeleton than it does making new skeleton. After the cut, use superglue gel to glue the torn/cut tissue to the skeleton. This will help prevent the flow in your tank from literally ripping the tissue off.
Keep hermit crabs away from the rescue coral for about a month. They will often go after dead tissue to the point of ripping away good tissue...which will ultimately kill the coral.
Quarantine:
I have an insane QT system, which is a requirement if you're rescuing corals in bulk. After dipping, my corals go into the first stage QT system for 30 days. If I find any issues, they are retreated, and then kept for another 30 days. Some corals have stayed in the first stage for 6 months or more. After the initial QT, I cut off any remaining dead skeleton, redip, and put into the second stage QT. Again, they stay there for 30 days or until healed. If I happen to find any issues, they are retreated, then sent back to the first stage.
Having a system like that is not feasible for everyone, and for most rescuers, that's fine. But, just be prepared...many pests can crop up long after the initial inspection.
Food:
For about the first month I'll feed my corals as if they were non-photosynthetic (about 3 times per week). I use my own pureed homemade blend of raw oysters, clams, shrimp, whatever other raw shellfish I can find, seaweed (red, green, brown), sugar, and garlic. Initially, this can be very difficult. If the coral refuses to extend tentacles, I'll wait until the lights have been off for about an hour, dose amino acids, wait another hour, then turn off all flow and drop sinking fish pellets right onto each mouth. It'll take a while, but the coral will eventually open its mouth. If you still have trouble, placing the coral into a container full of food will work as well (see all the non-photosynthetic tutorials).
Don't ever try to force feed a coral. If the coral's mouth is gaping open, do not put food into it. This food will rot, and will cause the coral to rot too. Also, remove all uneaten food before 30 minutes is up.
Lighting & Flow:
Keep the coral in a pretty low light/low flow area. After the coral starts to heal and recover, you should be able to move it slowly to a higher light/higher flow area.
Random Weird Tip
Bear with me here - I don't know why this works, but it seems to. An employee of a LFS mentioned an old employee of his used to squirt a teeny bit of Kent's Essential Elements onto corals that weren't doing well. I'm usually not a believer in random treatments like that, but I tried it anyway. Since my QT tanks are small, I could only dose about 1ml per week. I turned off all flow, and just squirted a teeeensy bit on each coral (up to a total of 1ml per week.) This is by no means a miracle treatment. However, I did notice that the corals I expected to die seemed to hold on a bit longer, and in some cases completely recover. I don't think I'd recommend this for someone who just has one coral to rescue, but if you have it on hand, you might want to try it.
I don't have a theory on why this works other than maybe my tanks are low in a trace element required during the healing process. But, dosing the tank does not seem to work as well as squirting the product directly on the coral. The product rapidly dissipates into the water, so again, I'm stumped. I'd love to hear anyone else's experience with this.
One last note:
Just be patient - know that you're doing a good thing to help save corals that would otherwise probably die. You'll still have some losses...but learn from those. The rewards will be worth it.