[anathag]

i have a new lionfish added to my tank last week, he has been feeding well, but has startedshowing sings of stress, with rapid breathing, and a discoloration on his tail and is not eating. anyone have any ideas of what could be wrong? thanks.

[leebca]

WELCOME TO REEFLAND!

Having a predatory fish for only one week and saying "it was eating well" and then "is not eating" is a little confusing. These fish don't eat but once or twice a week. So let's begin with this. What are you feeding this fish and how often have you tried to feed it?

I will need more information about your system and the fish, if I am going to try and help with this. Sorry to ask for so much information, but, the more information you can provide, the better the answers to your question. If you have a photo of the condition, that would be great, too.

Some additional information that may be useful:
How old is your tank? When did it originally cycle?
What is the size (dimensions and gallonage) of your aquarium? Does the gallonage include the volume from the sump and any refugium?
Do you use carbon, skimmer, mechanical or other chemical filtration?.
List all specimens & sizes in the tank (fish, inverts, corals, clams, snails, crabs, shrimp, etc.).
Do you use a quarantine tank and procedure?
Foods you use and feeding schedules.
How long have you had this fish? If the fish was recently acquired (6 weeks or less), two more questions: Did you treat it or give it a dip before it went into the aquarium? How did you acclimate it – what procedure?
Do you use any vitamins? Fat additives? Any elemental or other additives? Please list all.
Chemistries – you gave some. Do you test for Phosphate, alkalinity, calcium and magnesium? Please give actual current numbers for everything. Have these numbers been changing lately?
Water parameters – please give actual numbers (pH and your pH range, salinity or sp. gr. & range, temperature range)
Do you see any of the following in your system: hair algae; micro algae; cyanobacteria growths (red slime algae); dinoflagellate (zooxanthellae) growths; brown algae; diatom growth; slimes; off-colored patches on rock or substrate that are not coralline; etc.?
Water changes (how much and how often).
What is your source water? (Tap water, RO water, DI water, RO/DI, distilled, etc.)
List what you added or taken out of your aquarium system (living, decorations, and equipment) during the past 6 weeks.
Maintenance schedule. What have you done lately?