colour change..

Question
QUESTION: I'm hope you will be able to help me, as I've searched the web and asked the fish aquariums with no luck!! I have 2 basic fantails. 1 is googol eyed and black, and the other normal eyes white with orange/red spots). Both are active and eating normally. today i noticed the white fish has turned black. I read that it is quite normal for goldfish to change color, but not white to black. i have kept up to date with the maintanance of the water. (cleaned weekly, conditioned, filter cleaned) i provide new plants every week and every second day add a small amount of flakes. I have had the fish for about 2 months and they have never appeared to be ill.
Is this color change also common? If not what do i need to do?
i  hope you can help, and put my mind at ease. Thanks Leah

ANSWER: Hi Leah,
 Colour change is quite normal for many fishes, though from white to black does seem a bit extreme, though not necessarily anything bad.   I assume that when you say "cleaned weekly" you mean that you change some of the water (e.g., about 25%) each and every week?

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>


---------- FOLLOW-UP ----------

QUESTION: hello, i do change the water at least every 10 days and yes only 25% off the water. i also clean the filter at the same time. I was told that this can stress the fish so i brought a "destresser" from the shop.

Answer
Hi Leah,
 A 25% water change shouldn't stress your fish.  I generally avoid adding any "chemicals" to my tanks unless absolutely necessary.  Often the chemicals cause more problems than they solve. Plus the cost of chemicals can really add up (particularly if they don't do anything) and I currently have about 100 tanks.

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>