Fin rot or fin damage?

[Nautilus]

I can't tell. The fish right fin is close together and I can't take a good look at it. I am pretty sure it's a silver koi (walmart aren't that bright). I bought it like that, since the fish is a beautiful sight, plus the employee mistook the koi as a $2 fish so that's a sale right there. It was near the corner bottom and using only the left fin to stay upright. When the net came in, it was flying around crazy in the tank as the employee try to fish it out. I came home, set up a divider up, since my current ones are huge (two of the biggest are 4-5 inch across) and the tank (30-40 gal) is likely to be overstocked, all seemed normal. Seemed more active and calm, not like its sickly self in the walmart tank.

Anyways, the fin looks like it's been in a tussle, and read it'll heal up as long as the water condition remains clean. But I think I see slight hints of red, but it wasn't there before when I got him home and only today I am seeing it. Now I am thinking it's fin rot. And the odd part is that it doesn't lie near the floor as it did in the store. Sort of it more in a dazed hover, in one spot, then moves on.

The divider also brought out interesting behavior in the the current residents. I am thinking about removing it. Originally I was going to get another 40-55 gal tank and properly cycle the tank (I got a book on it, still not done with it yet) which the book says it takes a couple weeks.

[Andy_Dufresne]

Coming from Walmart I wouldnt put out fin rot at all. They dont take care of their fish very well at all. Well at least its like that at my local Walmart. And I would say that your tank is too small for those multiple Kois. Most of the time all it takes is time and a clean tank to start the fin to heal. If your worried its some kind of bacteria I would recommend putting it in another tank if you have one handy so your other fish dont catch what it has. There are meds that can help with healing fins, I personally have had a good experience with Melefix, but others on the forum dont like it as much as other meds.

Reason its acting differently than in the store is it has a much better living conditions, I would hope. As long as your tank is cycled and has partial water changes every week.

And yes it will take several weeks to cycle your tank properly. You can try to speed it up by placing media from your currently cycled tank into the new tank you are wanting to cycle.

Nick

[Nautilus]

I thought it was fin rot, but I usually heard it affects all the fins or at least more than one. I guess the reason it's not acting up now it that it's alone or tired from using one fin (my tank is a bit deeper). Cause walmart put like 50+ fishes in one 55g tank...and I just went back three days later and saw only almost a half still left (the more expensive ones).

My tank is overstocked and not well taken care of (finally know), but the ones who survived the abuse of many years are pretty hardy. So now that I know this, I am trying to get another tank. My plan is the get one around the same size (maybe 50 gal instead of a 30-40) if it fits. I will be sticking the 7 inch orange koi with black tips and the 5 1/2 inch shubunkin (not sure on what type; pretty sure it's the american one but the tail is short). Maybe the pleco or the catfish gets stuck in there.

I got one red-orange comet and a common but their scales are missing. I am not sure if it due to fighting, scrapes, or the pleco (I heard of stories pelcos sticking on goldfishes). But when I put the divider in, I placed them together with the newbie, since they weren't that big (around 2-3 inches) and it looked like they can't try swallowing him. They stuck mainly together, but when food came around they were fighting. Like chasing each other in a circle, mainly the common started it. So I separated the common.

I am not sure on treatment. Don't want to add stuff I don't know much about and stress out all the other fishes (ossmois presure?). If it's fin damage though, and not fin rot, how do I treat that?

By the way: Is a koi still a koi even if you don't see barrbels?

[Nautilus]

Bad news - little silver koi died.

Lasted a week...It died on the day I finally have time to get the items (tank, melefix, fish net, water testers, tank cover, fliter). I knew it was acting weird when it couldn't swim down. But I went to check today before I left, it was swimming around normally. This sucks: I even took two hours preparing it for the tank when I first got the fella. Bag Temperature, then pour some of the tank water in the bag, waited, and then scoop him out of the bag instead of pouring him in.

This is him with no flash.

Him flash on left side.

On the right


Disfigured right fin; it's not folded out completely otherwise you would see the rip. It's also red, but in the picture it's pinkish. Also, when it swam, the fin would be closed folded very closely to the body.



The tank mates & why I bought the divider
The biggies: One Koi, the other I am not sure what it is (used photoshop's autocolor to get rid of the yellow)

What I used for a net when I didn't have one; I hope it didn't affect the transport of the fish.

The tank w/ divider (autocolored)

Comet & common goldies; terrible shape they are in, but I have no idea why some of their scales are gone...(autocolored)



Also, there's a pleco that got HUGE and a Rapheal catfish. No pics cause they are extermely shy, angsty, and...fighters. You don't wanna mess.

[Cichlidsrule]

Plecos don't grow to the limit of their tank. If you let them, they'll get about three feet long. And yes, they can be quite territorial.

I've seen some koi that lost scales and seemed perfectly fine, but I'm not a koi keeper, so I wouldn't know.

Has your tank (which the silver koi was in) finished cycling? If not, then it could have been a few things.

New tank syndrome, which would make sense from the clamped fins and redness around the damaged fin.
The fish ripped or tore the fin from getting harassed by another fish or tearing it on something (like a plant), which caused an infection to set in. The high ammonia, nitrite and/or nitrate levels caused by overstocking the tank and/or an uncycled tank would have served to weaken your fishs' immune system and speed up the infection.
A mild case of fin/tail rot, which wouldn't have killed your fish (this quickly, anyway) but did because your fish's immune system was weakened.
The fish was young and died from an overstocked and/or uncycled tank.

I find it hard to completely confirm any of the above possibilities (I'm sure someone else on this forum knows more than I do about this sort of stuff :P) since the only symptom was really a damaged, pinkish fin. But if your tank hasn't finished cycling, a large (50%?) change of water should help speed it up. You should probably keep an eye out for any other signs of fin/tail rot in your other fishes, in case it really was that which did your little koi in.

[emc7]

I don't really know anything about koi (I had one for 3 hours and it jumped out of the tank and died) or fin-rot but I want to make one comment. 6-8 week long fishless cycling is for your first tank. Once you have a tank, and if your fish are in adverse conditions, such as overcrowded or incompatible tankmates, by all means fill up a new tank and move some of the fish. They will be better off. If you divide your existing filter media and fish between two tanks, chances are both tanks will be "cycled" in a only a couple weeks. If you do a large water change in the old tank, and fill the new tank with clean water, and use a double dose of Prime in the clean water, you may never see an ammonia spike. If your new tank is replacing the old tank, move all the fish and the old filter to the new tank and it will be instantly "cycled'. Wait several weeks before bringing home additional fish, but if you have more tank space available and your existing fish need it, don't wait because its not "cycled". The only time you might want to start from scratch is if you have a disease in your old tank. Even in that case, I would consider "cycling" the tank with one fish that is being chewed on or is bullying other fish. Reducing the load on the old tank is good for all the fish in it.

[JustOneMore20]

Do you have a pond to move the Koi to eventually? 30-40g or even 55g is not nearly enough room for a full grown Koi. They can get really large and I imagine they produce alot of waste.

Your tank definitely sounds overstocked (without knowing whats in it, exactly). And if you haven't been keeping up with water changes, I suspect fin rot. It is caused by poor water conditions.

[Nautilus]

No, the fin was already in a bad condition when I bought it. It wasn't pinkish or anything but definitely close to the side, it looked torn a bit but I wasn't sure since it rarely used it.

Hmm definitely going to reread on water condition. I don't do % changes (Not sure how that works out). I add more water, when the water evaporates. I take a wet cloth and wipe the white stuff on the sides before filling up.

As for an outdoor pound, no. We have the space. They just don't want to get an outdoor pound. I can...try a big tank. Nearby restaurant keeps two huge koi in those lobster tanks in restaurants.

[Cichlidsrule]

% change just means that much of the tank. For example...
Let's say you have a 40 gallon tank, and you wanted to change 25% of it. That means you remove 10 gallons of the water from your tank and dump it out, and put 10 gallons of new water back in (because 25% of 40 is 10 gallons, as I'm sure you know :P). Or if you wanted to change 50% of your 40 gallon tank, you'd change 20 gallons.