how to maintain the black color in a goldfish indoors?

[Death03]

Hi guys, I currently have a black "thai" ranchu in a 40g with 3 other ranchus. When I first got him he's really black but with a golden belly. I only have him for like two weeks right now and all of it's color is starting to turn gold-ish.

I read online that to keep goldfish really black they have to be exposed to sunlight but I currently don't have the luxury to do that since I keep all my fishes in an aquarium, and when I'll be home after work there would be no sun for me to expose him to lol. Also the seller where I bought him to keeps all his goldfish in a pond so he would be exposed to sunlight daily.

I currently ordered a "full spectrum" led lights thinking that it would help him retain his black colors, since right now I just have "regular" led lights in the tank. Do you think that would help?

His current diet is pellets (saki-hikari balanced, hikari lionhead, hikari wheat germ), peas, and vegetables.

Here is a comparison of when I first got him and today. As you can see he's really darker before



Any advice to keep/maintain the black color of a ranchu?

Thanks!

 

[Zanzag]

No advice to give sadly. but my guy, also tank kept, started out that black. Now that hes aged hes a beautiful metallic bronze color.

 

[TheWolfman]

Someone correct me if I’m wrong here, but it is my understanding that all black goldfish will lose their coloring and turn out gold eventually. What size though is down to genetics.

 

[duanes]

A bare bottom tank probably doesn't help, most fish tend to match their surroundings instinctively as a defensive mechanism.
Because you've only had it a couple weeks, aging should have little to do with the change, seems like an environmental reaction to have happened in such a short time.
I'd put it in a tank with a darker substrate, and some dark decor like logs, or stones, maybe some floating plants to see if it reverts.

 

[DThompson]

Mine only changed colors on his belly. Took about a year after I purchased him to fully turn like this. He's now been like this for about 6-8months. His eyeballs used to be all black as well but now they're orange which is kind of neat.

 

[Aquatic Aggression]

Goldfish can demelonize in an instant. Sadly the only things that are half proven to slow the process are sunlight and green water. The only goldfish that have solid black color genetics are moors and calicos. Most solid blue or black fish will change to white and pale orange. Sometimes when wen fish lose color they can aquire the yellow head.

 

[MatteoTheEnder22]

You can also try putting a fish safe uvb light bulb and making the surrounding more darker for the goldfish it helped with my oranda and black moor goldfish.

 

[Arthur11]

I have a 30 gallon goldfish tank. One of them is starting to turn black. I have read several articles about the causes of fish discoloration, one of which is melanophores, a type of fish skin cell that contains melanin. If the aquarium is placed in a dark place or has a dark and rocky bottom, these cells will produce more melanin, and the goldfish will begin to have dark spots on their bodies and fins.

 

[C. Breeze]

Like a Midas or a red devil or a flower horn. They will peel and there’s no real way of knowing how much or how soon or how long it will take

 

[xenacanth9]

Exactly