One Fish Dead In 24 Hours Another On The Way Out :-( :-(

[friendlyfishy777]

I lost one of my Corydoras Trilineatus 24 hours ago, he had been more timid than usual for two weeks, hiding a lot, but then he seemed to come out in the open to die! Now another of my Trilineatus who had previously been swimming about fine looks to be on the way out. I don't understand what's happening and feel desperate to help. I was going to be moving all four to a separate tank and adding to their numbers in a few weeks, making this all the more upsetting as I wonder if only being a group of four could have caused this. I've had the fish for three weeks now (brought them online). The other two are still swimming around fine and happy; in fact they actually seem less shy than usual. All other tank inhabitants’ behaviour hasn’t changed.


Tank details: 200l (30 Gallon) - powered by external filter Fluval 405. To add more oxygen to water I have the outlet slightly out of water, to do this the tank isn't filled to the top, so I'd say it was more like 160L of water. Bottom of tank is sand, there are many hiddening areas includeng a big peice of bog wood, the tank is moderately planted.

pH: 7.5

ammonia: 0

nitrite: 0

nitrate: An average of 35ppm. My tap water is crappy so it’s hard to get it anything below that.

Diet: Fish are fed on catfish pellets, a mix of fozen and freeze dried foods, as well as flake mini. I only put as much as what they will be eat within five mintutes. No food is left at all once everyone is finished, the hoplos in particilar are like vacuum cleaners.

tank temp: 24c, but there was a dip starting five days ago due to heater malfunction (causing heater to go to 22c – 23c on a number of occasions), since I’ve got two heaters in there to keep the temp correct.

Fish Symptoms: Paler in colour than before, top fin close to head, not eating, sitting on bottom – looks physically smaller somehow.

Volume and Frequency of water changes: two 30% water changes twice weekly as I’m in a high nitrate area.

Chemical Additives or Media in your tank: form media, 3 baskets of biomax and 1 basket of Seachem Matrix

Tank inhabitants: 3 Megalechis thoracata, 5 Corydoras aeneus, 4 Gold Laser Corydoras, 4 Corydoras Trilineatus (now down to three!), 6 Harlequin Rasboras.

Recent additions to your tank (living or decoration): Hornwort one week ago to help with nitrate

Exposure to chemicals: Seachem Prime concentrated conditioner at every water change

eSHa Gastropex Aquatic Snail Killer two weeks ago (did 75% water change after treatment course finished)

 

[friendlyfishy777]

Anyone have any advise at all to what might help/be the cause?

 

[eaglesaquarium]

That is a fairly high pH for cories.


But, ultimately, I think it come down to this:

eSHa Gastropex Aquatic Snail Killer two weeks ago (did 75% water change after treatment course finished)

There is no reason to use these types of chemicals in your tank... ever. There are much more natural (and less dangerous) ways to deal with snails.

The Snail killer probably had copper in it.


I would complete as big a water change as I can possibly do, AGAIN and rapidly. Continue to do these water changes until you see the cory starting to look better. There is no way to remove this stuff except by way of water changes. And as nice as you think a 75% water change is, it still leaves far too much in the tank for some species to be comfortable with it. Corys are a scaleless fish, and they are far more sensitive to medications, etc. than many other fish. Usually when dosing meds with corys in the tank the recommendation is to use a half dose, rather than the whole thing.

 

[pyrofishtoo]

Copper is bad! My other thought is the here in Canada, the city/municipality will sometimes shock the water system in the fall and the spring. Our water supply is chloramine which is deadly so I have to use a good quality water conditioner. What is your water treated with?

 

[the_lock_man]

That is a fairly high pH for cories.


But, ultimately, I think it come down to this:

eSHa Gastropex Aquatic Snail Killer two weeks ago (did 75% water change after treatment course finished)

There is no reason to use these types of chemicals in your tank... ever. There are much more natural (and less dangerous) ways to deal with snails.

The Snail killer probably had copper in it.


I would complete as big a water change as I can possibly do, AGAIN and rapidly. Continue to do these water changes until you see the cory starting to look better. There is no way to remove this stuff except by way of water changes. And as nice as you think a 75% water change is, it still leaves far too much in the tank for some species to be comfortable with it. Corys are a scaleless fish, and they are far more sensitive to medications, etc. than many other fish. Usually when dosing meds with corys in the tank the recommendation is to use a half dose, rather than the whole thing.

I would have thought that an activated carbon cartridge in the filter would help with removal of the medication.

 

[friendlyfishy777]

I did further big water changes but sadly the little guy didn't make it.

It seems as though it was the eSHa Gastropex, I feel so terrible. It said on the package it was "safe for all fish" and you didn't even need to do a water change after treatment. I'm glad I did a 75% water change after treatment, despite it saying that, otherwise more of my darlings could have died.

Never again...

 

[eaglesaquarium]

I would have thought that an activated carbon cartridge in the filter would help with removal of the medication.

IMO, removing the meds physically with a water change is preferred, especially when sensitive fish are involved. The carbon will take longer and may not removed completely, because the carbon will be removing some other things as well as the meds. Also, unless it is high quality stuff, it won't have as much surface area. Depending on the amount of meds you had to dose, it might be more than it can reasonably handle. IMO, it is safer to remove it immediately and stress the fish by having less exposure to the meds needlessly.

I did further big water changes but sadly the little guy didn't make it.

It seems as though it was the eSHa Gastropex, I feel so terrible. It said on the package it was safe for all fish and you didn't even need to do a water change after treament. I'm glad I did a 75% water change after despite it saying that otherwise more of my darlings could have dried.

Never again...

I know how you feel. Just remember that cories are very different than other fish, because they are scaleless. Generally, the recommendation is to treat them at HALF the regular dose whenever using any kind of meds. Also, unless the entire tank is infected with something, it is generally best to remove it from the regular tank and place it into a quarantine tank. (Be sure to do a MASSIVE water change on the main tank once the sick fish is removed in an effort to remove as much of the pathogen as possible. Of course, this isn't always the case, especially with ich, where the tank itself is infected as much as the fish are.

Finally, don't believe everything you read on the labels of fish care products, ESPECIALLY the "safe for all fish" type things. Do your own research and double check with experienced fishkeepers (not necessarily those at the LFS). Problems like snails happen, but for every problem there is generally a solution. Very rarely is the only solution adding a chemical to the tank. Whenever possible try to deal with it mechanically first.