Koi fish getting red areas on face etc.

Question
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Followup To
Question -
My friend has two Koi fish. She has had them for about eight months. She has noticed that one of them is getting red areas on it's face, spine and fins. It is eating OK. Do you have any advice? Are these signs of something wrong?
Answer -
Hi Vicky;

What size tank or pond are they in?
How big are they?
How often does the tank get water changes?

The tank is 30 gallons
They are about eleven inches
The water is changed about every 6 months
Yes it does have a filter.
Does it have a filter?

Let me know as soon as you can....

Followups Welcome

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Chris Robbins

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Answer
Hi Vicky;

Oh my goodness.....these fish need some clean water. All fish need 25% of their tank water changed at least every two weeks. The fish may be suffering from skin irritation from waste build-up. Poor guys. Tell the owner not to make too large of a change at once though. It could shock the fish and they could die. To get things straightened out slowly, change 25% of the water every day for a week. That sounds like a lot ot work, but assure her that it is the safest way to get things back in order. Once the water changes are being done, the redness may go away on it's own. Be sure to remind her to use a good water conditioner every time water is replaced. If the redness does not improve in a week, get back to me and I can recommend a few more things.

It is important not to clean the filter during these changes. That would be too much disturbance of the biological system at once. Wait until after the crisis is over for a week or so.

These poor fellas are way too big for the tank too and need more room. Fish that big should not be in anything smaller than 55 gallons. The general rule of thumb is that the fish must be able to fit along the shortest side of the tank without bending and the tank must be tall enough that the fish can stretch full length up and down too. Then, the tank should be about 4 times their length at the very minimum. Koi get to be 3 feet long and are very strong fish that can break lids and and jump out too. That's why they are usually kept in ponds outside.

I hope they do better and turn out okay. I am sure they are very stressed right now.

Followups Welcome

At Your Service;
Chris Robbins

Come on over and join us on the freshwater fish forum at About.com to get even more information too;
http://freshaquarium.about.com/od/questionsanswers/a/naavigateforum.htm

My member name is ChrisR62. See You There!