Ugh. It's been a very bad week for our aquarium. Three fish dead in less than a week. Phillip died due to my negligence (I took out a rock with him in it unknowingly, and he asphyxiated...presumably). Chantal died from ich. Elton died from ich and my failure to adequately oxygenate the hospital tank. Hard lessons learned.
After waking up one morning and seeing ick covering Chantal's eyes and Elton's fins, I resolved to do a freshwater dip. I added an ich treatment containing methylene blue and formalin for increased efficacy. I scooped them into the container with the ich treatment for 1 minute, followed by another dip in just freshwater for another minute before putting them back into the tank. The 2nd dip was to be extra sure no formalin or methylene blue got into the main tank, where it could kill my shrimp and coral. Following the directions of Goemans and Ichinotsubo in "The Marine Fish Health and Feeding Handbook" (absolutely awesome book), I matched the pH with baking soda and used a heater and thermometer to match the temps, thereby lessening the shock of the dip.
Catching them was certainly not easy. Luckily, they hid in the same rock. I picked up the rock, shook them out into the freshwater dip, and whallah. Problem solved. The next morning, Chantal was lying on a rock, breathing rapidly. She looked terrible. Elton looked much better, white spots much less prevalent. I should have LEFT THEM ALONE. Chantal was a goner but Elton would have made it out okay. This is where I made my irreversible mistake.
Panicked that the ich would infect the entire tank, I rushed out to purchase a 10-gallon hospital/quarantine tank. I got a HOB (hang-on-back) filter, an air pump (to increase oxygen), a heater, a thermometer, and a couple of stupid ornaments for the fish to hide in. So far, so good. I mixed saltwater at a salinity of 1.020 (instead of the main tank's 1.025). This was probably not a great idea. Although lowering the salinity to 1.015 kills ich, a huge change in salinity will shock the already weakened fish, further risking death. It would have been better to gradually lower the salinity over a longer period (like a week). Then, I took out the carbon filter and treated with the ich medicine (methlyene blue/formalin). And this was my fatal mistake. Although these medicines can be used in dips, they are horrible for long periods in a hospital tank, particularly formalin. Formalin sucks all the dissolved oxygen out of the water, suffocating the fish.
Chantal died pretty quickly. Elton seemed fine when I first put him in the hospital tank. By morning, he was on the bottom, lying on his side, gasping for air. I immediately put him back in the main tank where he died within an hour.
I am so mad at myself. I basically killed a totally salvagable fish (Elton). I don't think I could have saved Chantal but Elton would have recovered if I had left him alone. Basically, I killed them by suffocating them with the formalin in the hospital tank. Not to mention all the stress I put on them. I did what I thought was best at the time.
I've learned a lot from my mistakes:
1. Don't overcrowd.
I got too many fish, too quickly. I am now focusing on the fish I have in the tank. I did a small water change after removing the sick fish to try to dilute out the ich in the tank. The remaining fish all seem very healthy and happy. So basically, no more new fish!
2. Be conservative with sick fish.
Stress can easily kill a fish. Think twice before trying to do anything to the fish that involves netting them out of the tank (freshwater dips, hospital tanks, etc.). Start with a water change and leaving them alone.
3. Always quarantine new fish.
I learned this the hard way. I've cleaned out my hospital tank and will use it for quarantining in the future.
4. Always put an airstone in a hospital tank for vigourous aeration.
Many medicines are very toxic to fish. I will never use formalin in the hospital tank again. Only for dips. If I had to do it all over again, I would have slowly decreased the salinity and slowly increased the temperature to kill the ich in the hospital tank. This would have been the least stressful to the fish.
Poor little Chantal. She was never very healthy to begin with.