Guppy emergency

[Alien Anna]

Hi, I have 8 fancy male guppies, along with 4 mollies, in my 120L tank. One of them was causing me some concern last week, and today when I was rearranging the tank decor, I found him lying on the bottom of the tank. On close inspection, he appeared to have white flecks on the edge of his tail so I think it may be that guppy tail-rot disease that killed off 4 others a few weeks ago.

The tank has salt in it (about one teaspoon per 12 litres) and I've been adding Melafix daily for a few days now, but I'd skipped a dose last night. It seems as if the second I stop treating, this guppy gets sick. So, my elderly pencilfish having died and the hospital tank cleaned out, I moved him into it with the Fluval 2 I keep as a back-up. I have added some Interpet "Finrot and Fungus" remedy (I don't think it's whitespot with all that salt and the high temperature) and I've added even more salt to make it up to about 2 teaspoons per 10L (I've run out of salt now, so it'll have to do).

Ofcourse, now he's swimming about like he's not got a care in the world and I'm wondering if he isn't a complete fraud?

Meanwhile, back at the livebearer tank another of my guppies has started acting crazy, shimmying and darting everywhere. I double-checked my water parameters (GH 14, KH 10, pH 8, NH3 and NO2 zero, NO3 25 ppm), which are the same as they've always been, and all my other fish are absolutely fine.

Is this fish sick too? What should I do? Has anyone any idea what's happening to my poor fish? I had a theory that my fancy guppies were perhaps rather over-bred and too delicate, but I am so careful with them it's untrue! I'm beginning to wonder if my tank's cursed or something!

 

[Liz05]

I can't tell you what to do about your guppy, but I can tell you that I have the exact same results with MelaFix. My black molly gets these white spots. I don't know what they are... ich, maybe, some other parasite.... so every week or so, I will have to raise the water temperature, and add some MelaFix.. in two days, it's gone... SO, after another day or so I stop. It always comes back. I've been dealing with this for about two months, and its always coming and going. It doesn't seem to bother him much, though, and none of my other fish get them, so I don't get too concerned about it anymore.
I wonder about the effectiveness of MelaFix altogether.
I had one fish with a fungal infection. Treated with MelaFix. Died.
I had a fish with popeye. Treated with MelaFix. Died.
And I wonder if the only reason my molly's spots go away is because of the raised water temperature.

Sorry for rambling. Anyway, my only suggestion would have to be to try something besides MelaFix. I find guppies to not be as hardy as they are supposed to be, at least in my experience.

 

[Alien Anna]

So far so good. I've treated the sick one with Interpet "Finrot and Fungus" and he seems absolutely fine. The other fish is swimming with his pals again so I don't know what to think. They certainly aren't hardy - I blame in-breeding