Please Help! Strange behavior in koi- Laying on bottom

[koipolloiza]

I'm very new here and very much an amateur. I don't breed koi, or show them or anything; I just putz around with my backyard pond for relaxation. Have been doing this for about 7 years maybe, but have never seen any of my fish behave the way a few of them are now. Everything was going wonderfully well this year. My pond is about 1500 gallons. Covered about 1/2 in shade. Water is in good condition. Various small-to-medium koi and goldfish (24?). New filter installed 1 week ago- great water flow. All fish doing great all season. Added 4 new koi 1 week ago also. The new ones adapted very quickly and everything was fine up until yesterday afternoon.

I'm not even sure if this is a "problem" per se, but I am worried. As of last evening, some fish have taken to just settling on the bottom of the pond- sometimes in the deep end, sometimes in the shallower areas. (So I don't think they're trying to get away from any predators.) One has even completely buried himself in between some rocks. The thing is, when food is offered, they will come to eat normally, and be active, but then go right back to laying motionless. (The buried one does not come out anymore). The ones that are laying are, for the most part, the new ones added last week- but there are one or two others who are showing this same behavior.

If anyone has any input into this, I would be very grateful.

[tranquility]

Sounds like you could have brought a problem in with the new additions...they may have had some hitchhikers...also the new filter--If its new it will take it a while for it to cycle-so if your feeding and the fish are pooping-I bet your ammonia and Nitrites are high...you say water is good...We need specifics on ph,ammonia, nitrites, and nitrates...24 fish in 1,500 gallons is really overstocked also...Do you have a testing kit?...If not you need to buy one and check all of them...
Lawanna

[ootyboy]

The key word here is "New Filter" in the past week. What happened to your old filter? Is it still in line? If you removed your old filter to install the new one, you are probably going through New Pond Syndrom!! I am going through it now, and it is nasty.

What kind of filter did you remove and what did you replace it with?

I spoke to a dealer a few months ago, and they told me about this concept of "Koi catching a cold". I am not sure if that is the official name, but it happens when you introduce new fish to a pond that has not had any new inhabitants for a long time -- more than a year or two! The rest of the fish seem to become lethargic and lay at the bottom and behave erratically. He tells me that this usually goes away after a couple of weeks. The reason, I brought this up is because it could be another reason for your fish behaving strangely.

[koipolloiza]

I guess I'm missing something- why would a new filter cause problems? Because of no bacteria build up?

I had a regular pool cartridge filter running, but the cartridge needed to be replaced. A new cartridge would have cost almost as much as the new filter, so I sprang for the new one; also because it's easier to clean. I got a Laguna Pressure-Flo. It has bio balls, layered foam, & UV. I also have a couple of layers of filter media and foam that the water passes through on it's way to the pump. I did not clean that when we put the new filter in. I added a dose of bacteria a few days after the installation. It was a day or so after that when the fish started acting weird.

[UP ALL NIGHT!!]

PH, ammonia, nitrites, and nitrates. You say your water is in good condition? This sounds urgent. The PRO'S can't help unless you give them this information. If you go else where for information be leery, and don't start dumping chemicals in the pond. L.

[ootyboy]

you have taken the established filter offline and added a new filter. This means that you have no nitrifying bacteria in the new filter to convert ammonia to nitirite and then nitrate. Your filter media will have to go through a few weeks of cycling before your water quality improves.

I guess the main question here is have you tested you water? If so what are the numbers?

[koipolloiza]

Quote: Originally Posted by UP ALL NIGHT!! PH, ammonia, nitrites, and nitrates. You say your water is in good condition? This sounds urgent. The PRO'S can't help unless you give them this information. If you go else where for information be leery, and don't start dumping chemicals in the pond. L.

PH= 7
AMMONIA= 0 MG/L
NITRITES= 0 MG/L
NITRATES= 2.5 MG/L

[koipolloiza]

4 fatalities on Sat. All 4 of the new ones I bought last week. I know everyone's going to say that I should have quarantined them, but I don't have the means to have a QT tank set up. It kills me that they were all absolutely fine Thursday afternoon. For some reason, I took some pond pics then, so I know they were all active and happy. Then by Thursday evening, the weird behavior started in a couple of them. 2 days later, all dead. Nothing on their bodies to indicate any probs, either. (I forgot to state that in my original post.) I wish I had never added those 4 fish- everything had been going so well all season up until then.....Should have just left well enough alone.

[Russell Peters]

Quote: Originally Posted by koipolloiza 4 fatalities on Sat. All 4 of the new ones I bought last week. I know everyone's going to say that I should have quarantined them, but I don't have the means to have a QT tank set up. It kills me that they were all absolutely fine Thursday afternoon. For some reason, I took some pond pics then, so I know they were all active and happy. Then by Thursday evening, the weird behavior started in a couple of them. 2 days later, all dead. Nothing on their bodies to indicate any probs, either. (I forgot to state that in my original post.) I wish I had never added those 4 fish- everything had been going so well all season up until then.....Should have just left well enough alone.

Are the rest of your Koi OK? Please keep an eye on them as they could become ill from the others.

[tranquility]

I can't emphasize that enough to my customers---your playin' Russian roulette when you do that...it takes something like this to convince them....sorry you had to go thru this---but, now you know why is sooo important to qt new arrivals...
Lawanna