July 16th, 2009, 11:28 AM
I have a goldfish, he's actually more silver than gold, that seems to change colour now and then. It has on several times turned black, the last time it happened was shortly after I put some Nutrafin Clear Fast into the tank. The fish is returning to his normal colour now, but this usually lasts a couple of weeks when he changes colour before he returns to normal. This does not happen to any of the other 5 goldfish. He does not seem to be effected by this change, still swims around like always, eats when feed..... Has anyone ever heard of this or seen it happen??
July 16th, 2009, 12:09 PM
Goldfish can turn black in response to stress. Some fish are more affected by stress than others and some will show their displeasure by bleaching out in colour or turning a blackish colour. You really should not need any additives to the tank, de-chlorinator should be the only thing you need and only if you have to do a drastic water change. Also additives and large water changes can throw off the delicate bacterial balance of the filter. If the bacterial system in the filter in the tank is damaged it can cause Ammonia from fish and food waste to build up before the filter recovers (This is called a mini cycle) and this is one of the main causes of stress in fish. When he is displaying black colour you should take a water sample in a clean container to your local fish shop (or pet shop with a good fish section) and get the water tested to see if any of the parameters are off.
July 21st, 2009, 08:27 PM
I think that this fish may be sick... For the last couple of days he has been acting different. He will swim around very aggresively then stop and sort of float for a couple of seconds and then do it all over again. The other morning he was actually jumping out of the water and hitting the canopy. Tonight I took a close look at him and noticed that his tail fin is starting to shread and he has what appears to be a growth at the end of his body where the tail meets, it is blueish in coulour and has the appearance of being fuzzy like. None of the other fish appear to have any kind of symptoms and are behaving as they normally do, so I don't know if this can spread to the other s or not...
July 24th, 2009, 07:36 AM
likely poor water quality. how many goldfish do you have and how large is the tank??
start doing some water changes- remove 25% of the water and replace it with water that is ONLY dechlorinated every other day for a few weeks and get some antibacterial FOOD and feed it to all of the fish. also get a bubble stone with an air pump to circulate the water around.
July 24th, 2009, 10:05 AM
Well, I no longer have that fish. The condition seemed to spread quickly so I opted to dispose of him before the other fish started getting whatever it was too. The water had been changed and treated (25%), prior to this fish getting sick, I tested all the levels and they came back normal, I have also started adding an antifungal remedy to the water. There are, now, 5 fish in the 30 gal tank.
July 25th, 2009, 09:30 AM
eek, 5in 30g??? thats pretty over stocked. general rule of thumb with goldies is 15g for the first one and 10g for each after. so 2 should be in 25g, 5 in 55g. they are really messy fish and because they were bred for so long to be small and compact, all of their organs are in places that cause issues in less than perfect conditions.
your ammonia and nitrite levels should be 0. no compromise. if your cycle is complete and stable, those values should be 0 and not budging. if they are not, please add aeration and do hefty water changes on the magnitude of 50% every other day or more.
your nitrAte levels should be under 40ppm. idealistically below 20ppm but i doubt you will ever see that as stocked as you are.
get a liquid regent test kit and keep a close eye on those along with your pH. your pH doesnt really matter as long as it is not extreme and it does not change. a STABLE pH is far more important than an IDEAL one.
goldfish are also notoriously over fed. given they are exceptional beggers and do danged cute when they eat. :D feed them goldie pellets once a day. skip pellets once or twice a week for shelled peas. it will keep things... moving along so to speak. :)
make sure you are doing a 50% water change at least twice a week.
goldfish should live at least 25 years. they have a reputation of being easy to keep and i think that is only because they seem to be easy to replace. if you take good care of them now, they will outlive any dog or cat.
July 25th, 2009, 09:32 AM
oh and stop the fungus treatment. without a positive ID as to what you have, it likely is doing nothing. it sounds to me like he had columnaris anyway.
July 25th, 2009, 07:37 PM
I picked up a test kit the other day, here are all the results. The numbers in the brackets indicate what the booklet suggested for "ideal":
PH High Range: 7.8 (7.5)
Ammonia: 0 (0)
Nitrite: 0 (0)
Nitrate: 20 (40 or less)
Up until now, I had only been testing the Nitrite and the levels have always come back normal.
July 26th, 2009, 08:55 AM
thats fantastic! those are great values to have. :) keep up on the water changes and you will also see some good growth on your fish. im sorry to say though you will have to upgrade your tank size at some point.
July 29th, 2009, 02:14 AM
I agree it sounded like columnaris because fungus generally does not spread that quickly, and columnaris, though generally CALLED fungus, is actually a bacteria, so you must treat with an antibiotic. The problem with antibiotics is that they can sometimes kill your biological bacteria either partially or fully (even if the medicine claims not to I have had it happen before) so it is best to treat in a quarantine tank rather than your main system (this actually goes for any medication but is imperative for antibiotics).
Columnaris is nasty and even with full treatment can take a fish. I have had more fish die with columnaris than recover, usually because columnaris shows up when the fish is already highly stressed, either from injury or another illness. I have seen one spot show up and overnight even with treatment cover the whole body.
If your other fish are healthy columnaris will USUALLY not spread from the infected fish to your other fish because the other fishes immune systems will fight it off.