[eFrey]

It is a blood fin tetra, there is a second blood fin tetra with the same issue. But the second one has less damage. I checked the water - ph 7.6 Ammonia 0-0.25, Nitrite 0, Nitrate 0. I do have pressure CO2.

 

[Raith]

What fish/creatures do you have in the tank? Have you just noticed this now and it was fine the day before?

 

[eFrey]

I didn't notice before work today. Fish mates - harlequin rasboras, rummynose tetras, neon tetras, 24k gold white cloud minnows, blue acara, gold chinese algae eater & SAE and serpae tetra

 

[Mr. Limpet]

I'd say that the prime suspects are the blue acaras.

 

[eFrey]

I have noticed that my blood fins have been chasing each other for over a week...

 

[Mr. Limpet]

I have noticed that my blood fins have been chasing each other for over a week...

I can't imagine bloodfins eating each other's faces.

 

[Griznatch]

I agree with Mr. Limpet. Cichlids can be pretty aggressive..

 

[PlantedRich]

Depending how closely you watch, I would say you have a disease problem more likely than fish eating each other as cichlids would rarely meet this type of fish face to face and take such small bites. They would be far more likely to rip and tear fins or certainly not stop until the fish was dead.
But then it is also very hard to tell what is going on from a simple picture. For instance, are the two spots on the black portion and one on the red, ich on the fish or something on the glass? I would not suggest ich as the cause for the missing flesh but it can often be the first sign of a wave of disease due to poor tank practice.

 

[eFrey]

Taking that into consideration, I have noticed that my FX4 out flow wasn't flowing as it should. I replaced two round filters and now the outflow is working properly. Could the lack of water flow cause an increase to disease?

 

[PlantedRich]

Taking that into consideration, I have noticed that my FX4 out flow wasn't flowing as it should. I replaced two round filters and now the outflow is working properly. Could the lack of water flow cause an increase to disease?

The good bacteria we use to deal with waste does require O2 to live and the more O2, the more bacteria, so in a second hand way the low may result in less good bacteria. One of the reasons we find filters good is that it does assure a steady flow of oxygen rich water.
When you say you replaced two round filters, do you mean you changed out two filter sponges in the filter?
If this is true, it is possible that you did lose a considerable amount of the bacteria in those two sponges.
When doing this, I might suggest it is wise to watch for any signs of an ammonia spike but that spike idea may also come from that single move/change being combined with other things we do at the same time.
We can often get away with doing small things like changing out filter media but if we do several small changes at the same time, we can get into trouble. Just random numbers that don't mean anything but if you lose 25 % from changing media, decide to lose 10 % more when you rearrange the plants and substrate, then maybe get really active and scrub down the walls, you can se how we can actually work too hard at doing things right!
A check of ammonia, nitrite, and more frequent water changes may be needed if you have done too much of this sort of small thing?

 

[eFrey]

It was the two filter sponges in the filter, And thanks for the advise!

 

[PlantedRich]

I do lots of cichlids and they do often have traits which make them less than ideal for tanks with other smaller fish but the acara are not a of the big bully sort and tend to be pretty easy to deal with. Not that there are not some which are rogue but, in general, they tend to ignore lots of other fish and just want to do their own thing, like set up a nest site and breed!
The only real trouble I have had with them was only partly their fault as I see it. I had corie catfish with them and corie seem to have very little idea of staying out of trouble as they seem to be totally blind to what other fish may think of as "their" space. That left the cories wandering thought the nest and the acara getting more and more active in keeping them out! They would nip and bump the cories and if they moved, fine but if the same corie was back in half a minute, things did get ugly and the acara would grab a fin and carry the corie out! The tank was heavily planted and catching cories in the bushes was not working too well but I did eventually get them moved out.
Kind of brings up the question of who is at fault if you get really upset with somebody walking through your bedroom and he doesn't take a warning?