Koi

Question
Hello,
  
  I have two Koi in a 29 gallon tank, recently they have begun to act odd. Currently they are floating around at the top of the tank with their tails pitched at a 45 degree angle. They have their heads close to the top of the water and appear to be gumming at the surface. I had recently used chemicals to deal with an algae bloom, 8 hours after the treatment this behavior began. Additionally, the two of them appear to have been coated with what looks like wood dust under the light. One appears to have a few scales dislodged and gooie growth on it's side. The substance doesn't have any red sores near it. Their fins also have red lines going through them they are more noticeable than usual.

I just changed the filter today, and did a partial water change about 5 gallons. I am at a loss of what to do and do not want to agitate the situation.

Answer
Hi Patrick,

I hear of a few different things going on here.

1. Floating at top, at an angle, trying to breathe the air up there or like they are having difficulty = Ammonia and nitrate poisoning.  They need water changes and new filtration media, as well as a spotless filter.  Clean the gravel while you're at it.

2. Algae bloom = Comes from high ammonia and nitrates.  Deadly to fish!  Clean the water and filtration - again, this is potentially deadly.

3. Koi require 50 gallons each as young fry (up to 3") and as adults 100 gallons.  They are not tank fish.  They are pond fish.

4. Fine dust coating = Probably Ich.  Treatment is to take the fish and put him in a hospital tank.  Heat the tank to 75 (for koi) and add 3 teaspoons of marine salt (not table salt) per gallon to the hospital tank.  Leave in there 5 days.

5. Scales dislodged and gooie growth on side = to different maladies.  Growth is probably skin fungus or a parasite.  Dislodged scales can mean Dropsy.  Let's get this fish into the exact same solution you have the other in.  

A recap = Please put both fish into a hospital tank, treat with 3 teaspoons of salt per gallon. Raise the temperature to 75 in there using a thermometer, and make sure it has a filtration unit sufficient enough for Koi.  Even on a temp basis, the filtration should be at least double-rated to their sized tank.  They are high wasters.

Meantime, while they are in the hospital for the next five days, clean their tank thoroughly.  Clean out the filter thoroughly.  Re-start the tank.  Don't boil gravel.  Instead, just wash it thoroughly in a bucket and then return it to the tank after you wash out the tank.  You don't want to kill all the beneficial bacteria by boiling.

However, you've named at least 3 diseases for the fish.  These are all 3, very contagious.  Should you treat them and then return them to their tank later, these diseases would kill them eventually for sure.  They would also reoccur.

The algae bloom is a sign of severe water neglect.  Algae cannot live without food to eat.  Food algae eats is poop.  That means the fish have been swimming in poop water.  The algae also eats other waste such as fish food.  For this reason, I suggest feeding the fish less.  Food should never hit the bottom.  Just a pinch, once a day and if they can eat it in 1 minute, that's enough food. :)

The sores and red lines - I want to address this to even moreso make a point.  They are from ammonia and nitrite poisoning.  It is like giving them small doses of stricnine (although completely chemically different) and they are being tortured to death by the poop in the water.  Ammonia and nitrites are poison to the skin of the fish.  They die a slow, agonizing death if it's not treated immediately.

Don't worry about agitating the situation.  It can't get worse, in my opinion.  I'm so sorry.  I hate delivering bad news, but the only way to solve this is to completely clean their environment.

Also, if they are truly Koi, not goldfish, then they should be in a pond.  They are going to be 2 to 3 feet long.  :)

Please consider it.

Patrick, I'm so very sorry you are undergoing such hard times with these little guys, but I know you love them and will pay attention to detail in making sure that they are treated immediately to solve these issues.  The fish may be dying now, but there is a possibility they can be saved with diligent, fast action. :)

If you have any questions, please write back.  I'm here to help you through this.

Renee