I'm pretty sure it's fin rot (although I have no experience with it), and not fin loss. It's definitely ratty, not cleanly chomped, and has slightly reddish/brown edges to some of it. And he's in the tank by himself, so unless he's suddenly started chewing on his tail at night...
It was fine on Thursday, and on Monday? Half gone! He seems to still be in good spirits, doing his little "food" dance, and flaring at himself energetically in the mirror.
I tested the water parameters using one of those Six Quick Dip test sticks on Monday. Results:
Total Hardness: Soft
Total Alkalinity: ~60
Temp: 80 deg
He is in a 3 gallon Eclipse tank, I do 25-30% water changes once a week. About 3 weeks ago, I had a little accident with the gravel vacuum. I got distracted as I was using it to remove water, and he swam up into it, thrashed about, and knocked off a few scales on his back by his top fin, on one side fin, and above one of his eyes. I replaced the water, added StressCoat (which I do every time I add water), and he recovered, or seemed to, in about 7-10 days. But then I noticed his gill area on one side seemed a little pale, then noticed later that day (yesterday) his tail was half gone!
I haven't seen him biting his tail at all. And he is in a tank all his own, with one fabric plant, 4 plastic ones, and a small bridge decoration, and none of them seem sharp.
I thought I was keeping the water clear (using a turkey baster to pick up his poops, as they seemed very solid & clumpy), but was not really vacuuming the gravel. When I did it yesterday, as I was going to clean out his tank totally (because of his bad fins, I was going to get rid of the gravel, clean everything, and use his tank to treat him), I noticed that there was quite a bit of yuck coming up from the gravel.
But I checked the water temp, got him out into a small container, drained all the water, threw out the gravel (all per a number of websites I read), cleaned the tank and all decorations with a scrubber & water (damaging the bridge, btw), then put him back in with just a few glass pebbles in the bottom, his bridge, the fabric plant, and two plastic ones.
Then I added Maracyn-TC (diluted in 3 oz water, 1 oz put into tank), added 3 tsp aquarium salt, mixed up water the same temp as before, added StressCoat to condition it, let it run for about 5 minutes, then put him back in.
He seems to be doing okay today, but then he seemed okay yesterday, even minus 1/2 his tail!
The tail seems to look the same, at least no more loss, but there is still a rust coloration along the veining of the tail.
Here are some pics of Big Blue:
Here is a pic of his tail before hand, on May 6th, 2008.
And here he was Monday, July 21, 2008:
And here is is July 22, 2008, after one day of treatment:
It's been recommended since I nuked his tank, screwing up the cycle, that I should do 100% water changes every day. But do I have to worry about diluting his medication if I do that? Should I just monitor for problems, and then change if things get out of balance? The Eclipse aquarium has the Bio Wheel, which the paperwork *said* wouldn't hurt (I hope), but I didn't add any bacterial culture in when I replaced the water, because of the antibiotics, and because the BioWheel should be fully set up...
Also, if I do 100% water changes, doesn't that mean I have to catch him and get him out of the tank? And won't that stress him more? Can I do 50-65% changes instead, so I can leave him in there without netting him?
I'm so worried. I probably should have just really rinsed out the gravel good, put it back in, along with this usual surroundings, so he wouldn't be stressed, but I *thought* I was doing the right thing. And it had been recommended by a few websites...
And do I need gravel in the bottom of my tank? I know it is a place for the good bacteria to grow, but if I have the Marineland Eclipse BioWheel system, which is supposed to build up that bacteria on the fins of the wheel, to detoxify the water... how important *is* the gravel?
Even after nuking his tank, I dip-tested it again, and all parameters were good (same as before).
Can anyone either reassure me I'm doing the right thing, or give me more advice? Me, and Big Blue, would really appreciate it!