Sick and dying 4 to 5 inch koi. New owner

[GBBUDD]

There are two things I would do that could help and not be throwing medications that may or not be needed. Those two things are some fresh water and increased aeration. Be sure to add dechlorinator to the water and do not change out all the water, just between 10-20 %. Increase aeration by adding an aerator or increasing the "splash factor" of the water return line, as agitating the waters surface adds oxygen.

Make sure the WATER TEMPS ARE SIMILAR thats is the easiest way to kill fish is a quick change in temps

 

[TheFishGuy]

Everyone has given good advice! 30 koi in 250 gallons is pretty overstocked, and they will grow quickly. I don’t keep a single koi in my 1800 gallon system, even that is being in the edge of too small.

Focus on doing a good water change right now ( with similar water temps, and treat the water with a dechlorinator ) and making sure they have plenty of oxygen, no more pond salt, these are freshwater fish, not saltwater.

 

[Sidzion25]

Your pH and KH are problems. The pH is too low, in the acidic range. The KH is non existent and needs to be raised. Your beneficial bacteria will have a hard time working well with a pH in the acidic range and no KH.

Your tank is very overstocked. You might get away with that if you have seriously excessive filtration.

If you can test with liquid tests, they would be much more accurate. The dip tests are not accurate, so they are pretty useless. Fin rot is caused by poor water quality, so I have some doubt about the results you are getting with those test strips.

Do you use a dechlorinator when adding water to the tank?

Tula has some good suggestions. I would follow her advice.

Please get some liquid tests for ammonia, nitrite, nitrate, KH and pH and post the results here. That will give us a much better idea of what is going on.

Gotcha.

There are two things I would do that could help and not be throwing medications that may or not be needed. Those two things are some fresh water and increased aeration. Be sure to add dechlorinator to the water and do not change out all the water, just between 10-20 %. Increase aeration by adding an aerator or increasing the "splash factor" of the water return line, as agitating the waters surface adds oxygen.

I have 4 sandstone with a separate oxygen pump for them.

 

[TheFishGuy]

Gotcha.

I have 4 sandstone with a separate oxygen pump for them.

Looks like you have a good amount of water movement, but that water is very dirty looking, like I said earlier, large water change. I would go for 50-75%. Just make sure tempatures are the same and dechlorinate the water.

 

[Sidzion25]

Everyone has given good advice! 30 koi in 250 gallons is pretty overstocked, and they will grow quickly. I don’t keep a single koi in my 1800 gallon system, even that is being in the edge of too small.

Focus on doing a good water change right now ( with similar water temps, and treat the water with a dechlorinator ) and making sure they have plenty of oxygen, no more pond salt, these are freshwater fish, not saltwater.

Black water koi out of florida where I bought them from said to put the salt in smh

 

[Sidzion25]

DO NOT rehome to anyone with fish it sounds like yours are not healthy, fin rot, parasites etc. i'd be less then pleased if i found out after the fact.

250 gallons for 30 fish left , was it the larger fish that died?

fin rot if not advanced can be cut off with a pair of scissors BUT you need to identify the spiny part of the fin on the outside edges of the fins do not cut those the fin it's self is like cutting a toe nail the spine is like cutting to deep into the cuticle. but before you do even think about it go to you tube see if you can find a video on it

30 plus 4" koi is crazy in that size tub 30 plus gold fish is too many

the good thing is you know the exact gallons to treat the fish but separate them to smaller groups as you learn. 5 koi at that size is pushing it and that's this year they will almost double in size to next year . Koi are NOT a fish for 250 gallons

Completely agree

 

[TheFishGuy]

Black water koi out of florida where I bought them from said to put the salt in smh

Salt is a common fish “treatment” And it can be therapeutic if used for a short time, however they are simply meant to be freshwater fish.

 

[WaterGardener]

If you can get the water straightened out, the fin rot should clear up on its own. But it looks like there is some serious work to do to get to that point.

I wouldn't recommend any surgery on those fish. That won't help anyway if they continue to live in polluted water.

Always fix the water first. Most problems come from bad water and giving the fish clean, healthy water will give them the chance to heal themselves.

 

[GBBUDD]

SALT IS A CHEAP mass fish keeper trick but it can be dangerous. was the salt diluted into say a pond for 5 gallon of water and dumped into the vat. or was the salt dumped into the vat dumping the salt in and stiring?

 

[Sidzion25]

SALT IS A CHEAP mass fish keeper trick but it can be dangerous. was the salt diluted into say a pond for 5 gallon of water and dumped into the vat. or was the salt dumped into the vat dumping the salt in and stiring?

I I diluted it first before I put it in the tank

 

[Sidzion25]

If you can get the water straightened out, the fin rot should clear up on its own. But it looks like there is some serious work to do to get to that point.

I wouldn't recommend any surgery on those fish. That won't help anyway if they continue to live in polluted water.

Always fix the water first. Most problems come from bad water and giving the fish clean, healthy water will give them the chance to heal themselves.

This is water right now

 

[Sidzion25]

Salt is a common fish “treatment” And it can be therapeutic if used for a short time, however they are simply meant to be freshwater fish.

Gotcha

 

[Sidzion25]

DO NOT rehome to anyone with fish it sounds like yours are not healthy, fin rot, parasites etc. i'd be less then pleased if i found out after the fact.

250 gallons for 30 fish left , was it the larger fish that died?

fin rot if not advanced can be cut off with a pair of scissors BUT you need to identify the spiny part of the fin on the outside edges of the fins do not cut those the fin it's self is like cutting a toe nail the spine is like cutting to deep into the cuticle. but before you do even think about it go to you tube see if you can find a video on it

30 plus 4" koi is crazy in that size tub 30 plus gold fish is too many

the good thing is you know the exact gallons to treat the fish but separate them to smaller groups as you learn. 5 koi at that size is pushing it and that's this year they will almost double in size to next year . Koi are NOT a fish for 250 gallons

Completely understand and agree

 

[Sidzion25]

If you can get the water straightened out, the fin rot should clear up on its own. But it looks like there is some serious work to do to get to that point.

I wouldn't recommend any surgery on those fish. That won't help anyway if they continue to live in polluted water.

Always fix the water first. Most problems come from bad water and giving the fish clean, healthy water will give them the chance to heal themselves.

The water right now

 

[Sidzion25]

Looks like you have a good amount of water movement, but that water is very dirty looking, like I said earlier, large water change. I would go for 50-75%. Just make sure tempatures are the same and dechlorinate the water.

The water right now. Would this be considered still dirty?