Adding new discus to established tank that has had issues in the past

[DiscusFanM]

Hi all,

I have had discus for only a year now and have definitely gone through my learning curve! Lost a few in the beginning due to newbie mistakes and disease but feel I finally have my WC routine down and have 5 discus that have all been healthy and eating strong for the past 8 months. I decided to order 4 more discus from the same source - they arrived 3 days ago and have been in QT - all look great, eating on the 2nd day.

Current setup:
120 Gallon
5 discus (now 4... keep reading)
25 cardinal tetras
4 cories
Sand substrate w/ pothos hanging outside of tank
2 110 Aqua clear HOB's and sponge filter
86 degrees, water parameters in line - ammonia 0, nitrite 0, nitrates 10

Here is my question:

Last night, out of the blue, one of my 5 current discus got bloated like a marble in his stomach - I treated right away with epsom salt but he died only an hour later, it happened so fast. He was the strongest eater in the tank and by far the most friendly, nearly jumping out of the water during feeding time and would even let me "pet" him. Could this be an old disease (bacterial infection?) from the beginning of my discus keeping resurfacing or likely a freak occurrence related to too much protein in the diet? This discus did seem to only like the beef heart, though I do feed a variety included Discus Hans flakes, discus granules, brine shrimp, mysis shrimp, freeze dried black worms, and frozen BH.

I am worried that my current tank may have something that will infect my new batch when they are introduced. Is there any way to know that my tank is disease free or is there something I can dose with as a preventative measure before introducing the new discus? I don't think my cardinal tetras were the healthiest bunch when I got them a year ago from my LFS, have had some loss there.

Side question: The new discus are about 4 inches and I didn't realize that my current ones are quite large compared to when I first got them - around 5.5 inches - is this size difference going to be an issue or no?

Thank you for any input!!

[Gabriel13]

I would not add anything new to the tank until this is sorted. Your new discus should be in QT for 6 weeks before adding to your display tank. Adding stressed discus to a tank that might be having problems is an issue just waiting to happen.

[Gabriel13]

Do you have any pics of your present fish? This might help others sort what's going on in your tank.

[discuspaul]

Firstly, the size difference between your existing and new discus should not be an issue apart from the normal establishment of pecking order when they are placed together.

Your 4 remaining discus have been together, healthy, and eating well for a lengthy period of time, and the demise of the 5th one appears to be a one-off issue (perhaps a serious bloat) which does not seem to be a cause for any concern of infectious cross-contamination.

Your quarantine should consist simply of observing the new group for only 2-3 weeks to satisfy yourself they are eating well and are obviously in healthy condition, before then introducing one of your remaining 4 to the QT tank with the new ones, & leaving them together for 4 to 6 weeks to determine whether there is any pathogenic cross-contamination. If all is well after that time, introduce the QT group of 5 into the main tank with the other 3.

And I suggest you lower your temp in the main tank to 82F.

[DiscusFanM]

Firstly, the size difference between your existing and new discus should not be an issue apart from the normal establishment of pecking order when they are placed together.

Your 4 remaining discus have been together, healthy, and eating well for a lengthy period of time, and the demise of the 5th one appears to be a one-off issue (perhaps a serious bloat) which does not seem to be a cause for any concern of infectious cross-contamination.

Your quarantine should consist simply of observing the new group for only 2-3 weeks to satisfy yourself they are eating well and are obviously in healthy condition, before then introducing one of your remaining 4 to the QT tank with the new ones, & leaving them together for 4 to 6 weeks to determine whether there is any pathogenic cross-contamination. If all is well after that time, introduce the QT group of 5 into the main tank with the other 3.

And I suggest you lower your temp in the main tank to 82F.



Thank you so much for your detailed response - I will do exactly this. What meds should I have on hand in case there is trouble once I introduce a current fish to my QT? And out of curiosity - why do you suggest 82 degrees?

[discuspaul]

Except under certain specific circumstances, on an ongoing basis 86 F is generally considered unnecessarily too warm for discus, particularly for near adult or adult discus. Many well-experienced discus-keepers maintain their tanks @ no more than 82-83 F at all times, and discus do well at that temp.
And BTW, the lower temp will be better suited for any discus tank-mates if you have a community tank, and any plants will do better if your tank is planted.

No real need to have any meds on hand until you know what kind of health issue, if any, has in fact developed from the QT, and you know what type of ailment you're then having to deal with. Since you're getting your discus from the same source as before, and your developed routine has kept them healthy & doing well over a sustained period of time, there is no reason to expect the QT will result in any unhealthy cross-contamination surfacing.

But the QT I've suggested is necessary since you know your existing fish are healthy, but you don't know anything about the new fish you're getting, even though they're from the same source as before. And if the new fish are carrying any pathogen your well-cared for fish are not immune to, then you risk the potential loss of only one of your existing fish.

[DiscusFanM]

Except under certain specific circumstances, on an ongoing basis 86 F is generally considered unnecessarily too warm for discus, particularly for near adult or adult discus. Many well-experienced discus-keepers maintain their tanks @ no more than 82-83 F at all times, and discus do well at that temp.

No real need to have any meds on hand until you know what kind of health issue, if any, has in fact developed from the QT, and you know what type of ailment you're then having to deal with. Since you're getting your discus from the same source as before, and your developed routine has kept them healthy & doing well over a sustained period of time, there is no reason to expect the QT will result in any unhealthy cross-contamination surfacing.

But the QT I've suggested is necessary since you know your existing fish are healthy, but you don't know anything about the new fish you're getting, even though they're from the same source as before. And if the new fish are carrying any pathogen your well-cared for fish are not immune to, then you risk the potential loss of only one of your existing fish.

Ok great info - thank you!!

[DiscusFanM]

Except under certain specific circumstances, on an ongoing basis 86 F is generally considered unnecessarily too warm for discus, particularly for near adult or adult discus. Many well-experienced discus-keepers maintain their tanks @ no more than 82-83 F at all times, and discus do well at that temp.
And BTW, the lower temp will be better suited for any discus tank-mates if you have a community tank, and any plants will do better if your tank is planted.

No real need to have any meds on hand until you know what kind of health issue, if any, has in fact developed from the QT, and you know what type of ailment you're then having to deal with. Since you're getting your discus from the same source as before, and your developed routine has kept them healthy & doing well over a sustained period of time, there is no reason to expect the QT will result in any unhealthy cross-contamination surfacing.

But the QT I've suggested is necessary since you know your existing fish are healthy, but you don't know anything about the new fish you're getting, even though they're from the same source as before. And if the new fish are carrying any pathogen your well-cared for fish are not immune to, then you risk the potential loss of only one of your existing fish.

Ok great info, I will be lowering my temp tomorrow - thank you! And I think I'm more concerned now about my current tank having some unknown pathogen in it (since I had issues when I first set it up and with my 5th original discus just passing) than my new arrivals. Would you recommend I actually add one from QT into my main tank in this scenario or still the opposite? I'm fairly confident in the health of this source's stock since I've gotten fish from him before, and like i mentioned, I'm pretty sure the cardinal tetras I received from my LFS may have caused some of my issues in the beginning since they didn't all look so good. Thank you for all of your advice!

[DiscusFanM]

One more addition... one of my current discus (I've had this one for a year now) has not been as aggressive with food as the other 3... He hangs in one spot while the 3 go crazy for food then will lazily peck at the fake plants throughout the day - he is not thin and has been like this for 8 months. At first I thought he was sick but could he be if he has been like this for long? He gets bullied pretty bad by another discus, who chases him away from food, but also bullies one of the other ones - so is not the bottom of the totem pole. He is not thin at all and does not have a pinched forehead... Pics posted below (solid red discus...RIP yellow discus)... maybe this has something to do with my other one getting bloat and he really does have something... or maybe I am paranoid now?!

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[discuspaul]

Ok great info, I will be lowering my temp tomorrow - thank you! And I think I'm more concerned now about my current tank having some unknown pathogen in it (since I had issues when I first set it up and with my 5th original discus just passing) than my new arrivals. Would you recommend I actually add one from QT into my main tank in this scenario or still the opposite? I'm fairly confident in the health of this source's stock since I've gotten fish from him before, and like i mentioned, I'm pretty sure the cardinal tetras I received from my LFS may have caused some of my issues in the beginning since they didn't all look so good. Thank you for all of your advice!

You say you had issues with this source's stock the first time around, and yet now you feel quite confident in his stock that you're getting the second time - is there a valid reason why this source's stock should be better now than it was before?

I sense that perhaps the problems the first time around were due to your initial inexperience with keeping discus, which could have resulted in insufficient attention to water quality & conditions as part of your daily routine. The very fact that, as you say, your discus have been eating well and healthy for the past 8 months strongly suggests that you've learned some things about discus-keeping, and they are indeed now in good condition (notwithstanding the sudden loss of one fish for an apparently obvious reason besides a pathogenic problem) - that much you know - but you know nothing of the health or otherwise condition of this new group of stock.

For this reason, I stick with my original suggestion, because the circumstances point to any problem potentially being with any new group rather than your existing group. And I don't think the Cardinals have possibly passed along any problem to your first discus, or it would have surfaced long before these many months have passed.

[discuspaul]

One more addition... one of my current discus (I've had this one for a year now) has not been as aggressive with food as the other 3... He hangs in one spot while the 3 go crazy for food then will lazily peck at the fake plants throughout the day - he is not thin and has been like this for 8 months. At first I thought he was sick but could he be if he has been like this for long? He gets bullied pretty bad by another discus, who chases him away from food, but also bullies one of the other ones - so is not the bottom of the totem pole. He is not thin at all and does not have a pinched forehead... Pics posted below (solid red discus...RIP yellow discus)... maybe this has something to do with my other one getting bloat and he really does have something... or maybe I am paranoid now?!

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115640
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Perhaps you are worrying a bit too much - your discus look to be in pretty good shape overall, and the cleanliness of your tank suggests they are being well looked after. The behavior you speak of relating to one discus (who looks quite good) doesn't seem particularly out of place - eating habits and appetite do vary from one individual to another - so I really don't feel you have much to be concerned about on that score.

[discuspaul]

M :
Having said all of the above though, I wish to add that they're your fish, you know them well & I don't know them at all, and if you truly believe your existing group is validly suspect, then why not go ahead ( as you mentioned) and reverse the QT by adding one of the new discus from QT into the main tank for a 4 to 6 week period to see what develops.
It's your call. I wish you well.