I have a black oranda on the way (online purchase) and would like to do as much as possible to retain its black color. After scouring multiple goldfish forums, I thought it might be helpful to consolidate all the factors that have been discussed and see if people's experiences are in line with what's being said. My goal is to provide an optimal environment for the oranda to keep its blackness and, if that is not possible, to remain as black as possible for as long as possible. good_very.gif

1. Genetics: There seems to be agreement that black goldfish with Thai bloodlines are better at keeping their black color than their Chinese counterparts. It is also generally acknowledged that the genetics of a fish sets the potential and limits for a fish's color. So, a black fish with red/white/gold scales built into its genetics will eventually express those colors with time. However, other factors can delay this inevitable change (see below.)

2. Light: Keeping black fish outdoors in partial or full sunlight seems to retain the color. For those with indoor tanks, having a light that mimics the intensity, duration, and spectrum of sunlight should achieve similar results. There seems to be differing opinions on the best type of light to use: some advocate a full spectrum bulb while others advocate a red-spectrum/plant growth bulb (4000-5500 K). What do you think?

3. Food: Avoid foods with color enhancing properties (i.e. beta-carotenoids). Wheat germ is helpful in retaining the black color. The effects of spirulina are unclear: it has been known to enhance both red and black colors. Can anyone confirm this?

4. Water: As another RG member demonstrated with a one month experiment, green or clear water are both acceptable for keeping black goldfish. Salt should not be added, temperature should be kept cool, and parameters (i.e. pH, carbonate & general hardness) maintained at the appropriate levels for goldfish.

5. Substrate: Light colored or white substrate to reflect light onto the belly of the fish to prevent the underside from changing color.

Have I missed anything? Please comment if your experiences agree or disagree with these observations.