Molly tale damaged - pse help..

[speed]

Hi guys - could you tell me whats with the mollies tale. It was fine this morning. The molly is lively and does not show any other signs of sickness or any other blemishes on its body. Is it fin rot? Also how do I treat it with a betta also in the tank (his fins are fine). The white rings are water marks on the outside of the glass.
Other fish are swordtails, platies, black & albino widow tetras, redfin sharks, phantom tetras.

 

[lmosness]

Not sure about the fin rot possibility. The only case I've seen of it was at a pet store that got some sick fish & they did not look good at all! Their fins were deteriorating. If it's just a torn fin, I would suggest something like Stress Coat. It helps heal damaged skin & fins. I had a dwarf gourami take a lot of agression out on my guppies. The only one that survived had a very torn up tail & it's been healing. Won't ever look normal again I'm sure but it's getting better w/ the Stress Coat. I've been told antibiotics of some type should be used also but I haven't tried that.

 

[Lotus]

It looks like damage to me. You have quite a few suspects in your mix, including the betta, tetras and shark. You can add some Melafix to help it heal.

 

[speed]

Thanks for the info - the tail has not become any worse over the last few days so it seems to be a bit of damage. As for the sharks, I will be getting rid of them and replace with a pleco rather - I believe they are very calm. I have 2 sharks a.t.m. and the larger one is picking on the smaller one but he leaves the other fish alone. As for the tetras - they seem to be very agressive to each other. My best fish a this stage is the betta - has got a very peaceful personality but he does not let the other fish boss him around - plus I have to feed him separate - in the opposite corner of the tank to the other fish. He likes attention that one.. I 'saved' him from a small little glass bowl in the LFS.
Am enjoying the fish. Its funny how each one seems to have his own nature.

 

[Lotus]

What size tank do you have? Common plecos are only suitable for large tanks (more than 75g). If you have a smaller tank, you should think about other fish.

Red-tailed sharks shouldn't be kept in pairs -- either one or more than six is the general rule of thumb to prevent aggression/deaths.

 

[lmosness]

We had a 55 gal & our pleco grew to 12 inches long. Later had to size down to a 30 gal & all was well there too. She lived to be at least 25 years old. Just couldn't have much other fish. I've grown to almost depend on having one pleco in there & I recently found out that Petco has a trade-in deal. Once your pleco is bigger than you want, you can bring it in for a smaller one & start over. Chinese algae eaters don't get as big as plecos so that's always an option (but, they have been known to nip at fins).

Wanted to add .... I was told that my pleco was unusual though ... she would actually swim across the top of the water & eat flakes too. There wasn't enough algae in the tank to keep her happy but between algae tablets & flakes she always seemed satisfied.

Pic of her attached (she just passed last month .... sad since she was almost as old as me)