Goldfish turning black!

[sharkweek178]

Ha ha, I was waiting for someone to ask that! Not confrontational at all, perfectly reasonable question.

I should have rephrased it to say I'm pretty certain that the tank is cycled. How do I know? Well, the tank has been running for several years, and housed freshwater tropicals (angels, danios, guppies, usual stuff). Recently, we decided to rehouse the tropicals in another tank, and use this one for goldfish. I was careful not to clean the glass, and to be very gentle when cleaning the filter medium. That way, the bacteria on the glass and in the filter should have survived the transition. Also, the tank has been running four about four weeks now, so any further cycling needed should have finished.

Make sense, or did I get the wrong idea?

That makes sense. You might want to get a test kit just to be certain. When any of my fish show any signs of illness, testing parameters is always my first step.

 

[Alice B]

my pond goldfish are all black when they first hatch and gradually most of them turn orange or orange and white. (eating bugs mean they are almost red when I say orange) But once in a while one stays black or black on top. I don't mind, I just feed the fish

 

[WhistlingBadger]

This is interesting. I used to seek out comets with black backs, just because I thought they looked interesting. Invariably they lost that coloration as they grew up and ended up solid yellow/orange. I even kept several black moors, and all of them lost their black coloring as they got older, turning a bright bronze-gold color. Disappointing.

This was 30+ years ago, mind you. Perhaps the moors have been bred to be more stable now. I've since learned that comets are usually born brownish-black colored (their "natural" coloration) and turn orange as they grow up. I've never heard of it going the other direction. Very interesting.

 

[Yossu]

That makes sense. You might want to get a test kit just to be certain. When any of my fish show any signs of illness, testing parameters is always my first step.

I know, I just haven't got round to it yet. Had the tank running for so long with the tropicals that I never needed them. All was running well, so I didn't bother testing. Lazy I know!

I don't mind, I just feed the fish

Well, yes, that's a sensible approach! I have been doing this, but was concerned in case this was anything serious. Sounds like it's not.

This was 30+ years ago, mind you. Perhaps the moors have been bred to be more stable now. I've since learned that comets are usually born brownish-black colored (their "natural" coloration) and turn orange as they grow up. I've never heard of it going the other direction. Very interesting.

Yeah, sure is. I'll be interested to see what happens with time. As long as it's healthy, I don't really mind. Preferred it orange, but it still looks good.

Thanks to all of you

 

[Bamf Comics]

I used to buy bags filled with 4 to 6" orange comets and drop them in my pond in the store and every time a few would turn a blue black and become almost impossible to find/catch against the black liner. I don't trust any goldfish or koi's colors until they're a couple years old.

 

[Yossu]

I used to buy bags filled with 4 to 6" orange comets and drop them in my pond in the store and every time a few would turn a blue black and become almost impossible to find/catch against the black liner. I don't trust any goldfish or koi's colors until they're a couple years old.

Interesting. No idea how old my fish are, but I guess not that old. Either way, not much I can do about it except wait and see what it ends up looking like!

 

[Yossu]

Just as a follow-up in case anyone is interested, the fish has now gone back to its original pure orange, without a trace of black!

No idea what happened, but it seems to have reverted itself.

Thanks again to all who advised