"I done a bad thing, George."
This morning's events reminded me of a quote I associate with Steinbeck's Of Mice and Men, "the best laid plans of mice and men oft go awry." That further reminded me of the characters in the book, Lenny and George. Lenny, who is short on mental faculties, consistently unwittingly undermines his friend and care taker George's attempts to establish a life for the two of them.
On 8/7/10 the last fish in my display tank succumbed to a parasite of some kind. My plan was to leave the tank fish-less for 6 - 8 weeks, which I understand would have all but ensured that the parasite had run its full life cycle and died off completely because it had no fish to feed on.
I started a 10 gallon quarantine tank and put 4 yellow tail damsels in it. The plan was to keep them in quarantine for 4 - 6 weeks and introduce them to the display tank after the latter had been fish-less for 6-8 weeks. I tested the water regularly and was surprised to find that there was no ammonia, nitrite, or nitrate. Over the course of the 2 weeks I had the damsels, I observed several of them nipping the same fish repeatedly. When they finally nipped the fish to death I decided that they were too aggressive for the type of tank I wanted to have and returned them last weekend.
I replaced the damsels with 4 blue/green chromis. I tested the water to make sure it was alright before going to the store and getting them. I noticed that one of them appeared to have some kind of sore or wound but hoped it would heal. I found it dead the next morning. Several days later I found another previously healthy chromis dead. I tested the water and found that the ammonia was high. I changed 50% of the water. I tested the water again a couple days later and the ammonia was still high, so I changed 50% of the water again.
This morning I found one of the 2 remaining chromis laying on the bottom of the tank on its side breathing heavily. The other was upright but also breathing heavily. I was just about to leave for work, was already running late, and just didn't have the time to perform a water change.
Certain that I would arrive home to find the 2 remaining chromis dead if I just left, I netted them out of the quarantine tank and put them in the display tank, forgetting all about the fact that I wanted the display tank to remain fishless for at least another 2 - 4 weeks to ensure the parasite was gone.
I realized the mistake I'd made above and beyond undercutting the quarantine period I wanted for the fish on my way to work.
"I done a bad thing, George."
The chromis that had been on its side died while I was still in front of the tank so I took it out. The other one is hopefully still alive and well, though. Or at least getting better. I am concerned that my adding the chromis to the display tank may result in not ridding the display tank of whatever parasite had killed all of my fish after all.
A) do a 100% water change on the quarantine tank when I get home and try to take the chromis out of the display tank and put it back in the quarantine tank? Is the presence of a small fish for one day enough to allow a parasite that may or may not still be present in the tank to make a comeback? Will I have "wasted" the past month of running the display tank fish-less even if I remove this fish when I get home and have to start over and wait another full 6 - 8 weeks?
B) Is it very likely that after running fish-less for a month (8/7/10 - 9/10/10) and being treated with PraziPro several times and Kick-Ich once (I did not continue the full course of treatment because there were no fish left in the tank to treat) that the parasite is gone and I can allow this fish to live at peace in the display tank rather than subject it to whatever is going on with the water in the quarantine tank?