Black Patches on Gold fish

[gsb_78]

I have 3 goldfishes in 50 gallon tank. For the last 6 days i have observed that
(1) A blackish color is developing on their tail fin ends and near their mouth.
Their links are as below:



(2) One goldfish is a little sluggish, remains in the middle tank region, aggressively feeds onto the given food, but gulps out all it has eaten within 1-2 minutes of eating.

Kindly guide as to what the reason could be.

[jaws]

are your goldfish very active?
how slugish is the slugish one?
how much do you feed them?
how long have you had them?
how long have been keeping fish?
i would say that if your gold fish are young then the black in the tail is just markings that have develped with growth, if your fish are active this is usually a good sighn that they are healthy, especially if they are eating well.
be carefull when feeding goldfish they are easily over feed,
and quite a lot of fish if you watch them will take in food then spit it back out.
my advice is only feed them a little do regular water changes with water conditioner (clorine and heavy metals in tap water are deadly)
if they start to not move around and eat then you have a problem and it probably is your water conditions.

[Ichthius]

Blackening of the tips of fins is an earlier sign of fin rot. Seems to be that he's developing fin and mouth rot. I'd treat with an antibacterial; maracyn two, possibly even melafix could clear it up.

How long have you had these goldfish? Any other inhabitants? How often do you clean the tank?

[Willow]

I was told once that black fin tips could mean ammonia burn. Do you have a test kit? If so, what are your ammonia readings?

[gsb_78]

Thanks for your prompt response.

My tank readings are as below:
Ph - 7.5
Ammonia - 0 mg/l
Nitrite - <0.3 mg/l
Nitrate - 12.5 mg/l

I have had these goldfish for the last 4 months now. There were no black patches initially, they have appeared very recently.I do vacumming and 10% water changes every week.And feed them 4-5 pellets each, twice a day.

While rest of fishes are all very active, its only this one goldfish which is very sluggish. Today it did not eat anything.Keeps swimming in the middle region of the tank and importantly i have seen it open a mouth very wide(as if it were yawning) since last 3 days.
Its other mates in the tank are:
2 more Goldfish
3 Silver Bala Sharks
4 Parrots
2 Angel
I know its a wrong combination but as i later realised that vendor had given me a wrong combination(When i bought the new tank 4 months back) and neither was he wiling to take them back nor i could find an alternative arrangement for them, so I decided to keep them together.

P.S: On closer observation I have seen these black patches have also started appearing on 1 Parrot.

Their Pics with black patches are given below for your kind reference:

[emc7]

In my experience, goldfish tend to lose black pigment as they age, not gain it.

[neilfishguy]

that tank is way overstocked and I think you should be doing more waterchanges

[Obsidian]

As mentioned previously this is very likely the beginning signs of Fin Rot. You can increase the amount of water you change during your weekly changes, to at least 40%. You can add appropriate amounts of freshwater salt, which is healing to the fishies. Follow directions on the container. Subsequent water changes will remove the salt when treatment is done. There are also medications you can use but I do not know much about those so will not comment here. Often salt plus a temperature rise is helpful, but since Goldfish are coldwater fish I would be careful with that and research it before proceeding, if I were you. Of course the other tropicals in the tank will love the increase. Depending on the temperature you are keeping it at now you could also research what the effects of keeping a coldwater fish in warmer water is.

[emc7]

Try posting in the disease section. Google fin-rot.

tank is way overstocked

Have to agree with this. I thought you were pushing it with 3 goldfish in 50 gallon. You have: 5 Goldfish, 3 Silver Bala Sharks, 4 Parrots, 2 Angels in 50 gallons?

Clean water is the best medicine.

You can increase the amount of water you change during your weekly changes, to at least 40%.

so I agree with this too, or change 10% every day.

Your water quality numbers don't look too bad, but as those fish grow, you will have a hard time keeping the water quality up. Poor water quality can lead to disease as can stress from incompatible tankmates, and conditions that don't match as fishes requirements, like the wrong temperature. So treat for fin-rot, but don't expect things to go smoothly longterm. IMO your stocking is not sustainable (if disease doesn't kill them, the parrots will).

I don't suppose you can start digging two ponds? One for the goldfish (unheated), another for the parrots and sharks (heated) and leave only the angels in the tank.

[gsb_78]

One of my Goldfish which was on fasting for the past 6 days now died today evening. I found it floating bellyup on water surface. Dunno what happened!!!