Fin Rot

[Green Baron]

Recently, the Black Tetras and Harlequins in my planted tank have been plagued with Fin Rot :-( I quarentined the affected fishes, treated them with MelaFix and return them to the main tank after they recovered but the fin rot keeps recurring !

I have not added any new fish to the tank. The only thing I have added are a few plants of Aponogetons I bought from Teo.

Any suggestion as to what I should do ? Should I change water more frequently (more than once a week) or wash the external filter ?

[|squee|]

Gan,

I think washing the external fliter and changing a bit of water will help. All the reading I've done mentioned water changes, salt ( for livebearers, but I do not know if it works for tetras as well. ).

This site kind of summaries everything: http://freshaquarium.about.com/cs/disease/p/finrot.htm

The main cause is poor water conditions. So probably your fliter needs a good wash.

Just my two cents,

[timebomb]

The only thing I have added are a few plants of Aponogetons I bought from Teo.

Gan, the Aponogetons at Teo's are usually grown emersed in their cement tanks. As far as I know, such plants come with a lot of undesirable creatures. Chances are your fish are suffering from fin rot because the plants brought some parasites with them. I don't know if it's a good idea to wash the filter as sometimes, it can make things worse.

Loh K L

[hobbit6003]

Hi Gan,

The signs of finrot, may not be a result of a primary bacterial infection.

There're many unfavourable water condition that can result in apparent finrot. This includes a high pH and ammonia toxicity. The combo of the two can be fatal at times.

With the above, the membranes between the fin rays would disintegrate first. This results in what we called the Frayed Fin Syndrome. Besides high pH and ammonia toxicity causing frayed fins, fish being subjected to chronic stress, can also display such a sign. Basically, it is believed that stress triggers off an autoimmune response that results in ischaemia (tissue death as a result of lack of oxygen) of the tissue, where the occluded blood capillaries supply.


Of course, as the fraying of fins get worse and the water condition continue to be unfavourable, secondary bacterial infection would then set in. What you'd see now, is the blunting of the fin edges, and the fins would have blunt whitish edges, and would get smaller and smaller. In severe cases, this may become just a stump.

I think if finrot keep recurring, then you should really look into your water condition, and perhaps what could have induced stress to the fish (eg. agression, overcrowding, unfavourable living condition)

In fact, it is always good practice to measure the basic water parameters. This will usually gives us alot clues to work on later.

Cheers,

Kenny

[Green Baron]

Thanks for all the advises ! They are in line with what I read in the Internet, i.e. Fin Rot is usually casued by stress and unfavourable water condition. I don't have high bioload and I change 25% of the water every week and I test for ph and kh, once a while ;-). I just tested it last week and ph is around 6.2 though my usualy PH is ~6.5.

The last time I washed my filter was about 3 months back. I did some uprooting and replanting recently so maybe the leakage of base fertliser could be one of the culprits. I have decided to wash the filter and change another 30% water. I will monitor and keep you guys updated with the progress.

Thanks