Why Did My Discus Die?

[katetee]

I bought a orange checkerboard discus about 3 months ago and put him in a 90 litre tank with another slighly bigger cobalt blue discus which ive had for about a year. When i first introduced the checkerboard into the tank he was bullied by the other discus for a few days but it calmed down and they lived relatvily peacefully together. After a couple of weeks i noticed the checkedboard had lil bits missing from his tail/fins but it didnt seem to bother him and i just thought it might have been where the blue discus had been chasing him in those 1st few days. Anyway - yesterday he seemed a bit 'off' just sitting near the heater not really swimming round much and just thought id keep an eye on him till monday where i could take him to the pet shop. He hadnt really moved today when i looked him this morning - we went out for the day and he was dead when i got back he was in a terrible state (which he wasnt the night before for sure) with his eyes bulging out and redness around his gills. I last did a 70% water change last week. I've since tested the water at the results were all within normal readings apart from the ph which was low (but it has always been low and id tried using the ph up from pets at home) So does anyone know why he went downhill so fast and suddenly? I mean obv im a bit gutted since i paid £30 for him and he was gorgeous

 

[Tolak]

Please fill this out to help us help you, it's just the standard form;

Tank size:
pH:
ammonia:
nitrite:
nitrate:
kH:
gH:
tank temp:

Fish Symptoms (include full description including lesion, color, location, fish behavior):

Volume and Frequency of water changes:

Chemical Additives or Media in your tank:

Tank inhabitants:

Recent additions to your tank (living or decoration):

Exposure to chemicals:

Digital photo (include if possible):

I always like to add to this; what make & model of filtration, what have you been feeding them, and what are the actual tank measurements?

Off the top of my head, that tank is rather small for two discus. I've seen breeders keep large breeding pairs in 29 gallon tanks, but they change an amazing amount of water, large water changes every other day. Another thing is staying by the heater, which I'm assuming is towards the back, which may indicate an internal protozoan issue.

 

[Assaye]

I bought a orange checkerboard discus about 3 months ago and put him in a 90 litre tank with another slighly bigger cobalt blue discus which ive had for about a year. When i first introduced the checkerboard into the tank he was bullied by the other discus for a few days but it calmed down and they lived relatvily peacefully together. After a couple of weeks i noticed the checkedboard had lil bits missing from his tail/fins but it didnt seem to bother him and i just thought it might have been where the blue discus had been chasing him in those 1st few days. Anyway - yesterday he seemed a bit 'off' just sitting near the heater not really swimming round much and just thought id keep an eye on him till monday where i could take him to the pet shop. He hadnt really moved today when i looked him this morning - we went out for the day and he was dead when i got back he was in a terrible state (which he wasnt the night before for sure) with his eyes bulging out and redness around his gills. I last did a 70% water change last week. I've since tested the water at the results were all within normal readings apart from the ph which was low (but it has always been low and id tried using the ph up from pets at home) So does anyone know why he went downhill so fast and suddenly? I mean obv im a bit gutted since i paid £30 for him and he was gorgeous

For a start, 90 litres is no way big enough for discus. These guys can get to 8 inches x 8 inches and need much, much bigger tanks. Tanks that are too small increase the risk of poor water conditions and also put a huge amount of stress on the fish, which can be fatal. I would recommend a 18" x 18" x 48" tank (so 1.5 foot x 1.5 foot x 4 foot) tank.

Discus are fish that generally need a very high level of care. They need large weekly water changes, low pH and soft water. Many keepers spend the extra and get RO water for their discus because they benefit from such specific water conditions. Why did you use pH Up product for discus? How low is your pH? Using these pH adjusting products generally causes more problems than they solve and if used carelessly, will cause the fish to become rather unwell due to the sudden change in pH and water chemistry.

You say readings for other things were normal - what did you test and what exact results did you get? Normal is a very subjective thing and many people (including pet shops) will say certain bad readings are OK simply because they don't actually understand why they mean.

Dead fish tend to look pretty awful. Apart from seeming "off", what exact symptoms did he have? Any redness? Heavy breathing? Swimming badly?

 

[katetee]

the tank size is 90l (which as u pointed out is probs a bit small for 2 discus but with them only been quite small i thought id just upgrade when they got bigger)

ph is 6.4 (as i said low - but they seemed to cope after having tried to raise it)

No3 -10
no2 - 1
gh - 8od
kh - 6od
cl2 - 0

Temp is currently 28 degrees

I do a 70-805 change once a month which i did last weeks and a 10% every week

I have a ehiem water filter (dont know the model off the top of my head)


Other tank inhabitants are - 1 barb, 2 mollies and 2 other small ones which i cant remember the name of!

The discus which has died was the last addition to the tank, last night he looked normal on colour, eyes ect he was just staying near the back of the tank where the heater is. When i found him he was pale with bulging eyes which had like a film over them and redness around the gills, his fins where also all 'raggy' but as i said that wasnt the case last night and none of the other fish seem to be affected

Thanks for your help

 

[Assaye]

the tank size is 90l (which as u pointed out is probs a bit small for 2 discus but with them only been quite small i thought id just upgrade when they got bigger)

Problem with that is often the fish have become stressed by trying to grow in a tank that is too small for them and the damage gets done. Some fish will be fine to be upgraded but with big fish like discus, many people can't (or won't) get the big tanks they need but still buy them with the intention of upgrading, despite the fact that the fish may become damaged.

Be honest with yourself - can you get a 4 foot long tank? If it's a no, sell or rehome the discus. Don't try to keep them in such a small tank.

ph is 6.4 (as i said low - but they seemed to cope after having tried to raise it)

A pH of 6.4 is fine, I don't know why you were worrying. It's quite low for some species but for discus it is fine. It is not fine, however, for mollies. Many pet shops don't give a flying fig about your pH or hardness and if they do say anything, it will usually be very wrong. Many places tell people they need a pH of 7 for everything or will say that a pH or 6 or 8 it dangerous and must be raised. All rubbish. They also don't tend to know which species require what kind of pH or hardness to their water. For instance - mollies and discus should not be in the same tank as they are both sensitive to the pH of their water and need totally different pH. Discus need it low, mollies need it high. Whoever sold you those was an idiot and shouldn't be working with animals.

No3 -10
no2 - 1
gh - 8od
kh - 6od
cl2 - 0

I do a 70-805 change once a month which i did last weeks and a 10% every week

NO2 is 1? As in, 1.0 mg/l or ppm (which is the same thing, btw)?

That is a lethal level. That looks like a small number but with NO2 (nitrite), it must be at ZERO all the time. Even 0.25 is too much. This causes very nasty nerve damage and brain damage and WILL kill fish.

With discus I would recommend about 40% a week for a healthy tank but as yours is unhealthy (from the high level if nitrite(, you need to test your water every day and do large (50-90%) daily water changes to keep that level reading at zero.

What is your ammonia reading? Are you using test strips? These are pretty rubbish and with delicate fish like discus you need to have really good quality, accurate test kits. Get a liquid test kit and make sure it includes tests for ammonia, nitrite, nitrate and pH.

Ammonia MUST be zero
Nitrite MUST be zero
Nitrate should be kept under 20 for discus
pH should be low and stable

Other tank inhabitants are - 1 barb, 2 mollies and 2 other small ones which i cant remember the name of!

Barbs should be kept in much larger groups - at least 6 but the more the better. What kind of barbs? Essential to know as some are small and peaceful, some are very nippy and some get HUGE. In a small group they'll be miserable (even if you can't tell) and will be more likely to nip and harass the other fish (which may happen at night so you might not see it).

Also important to know what the other two are, and ideally what sex your mollies are (although that's a different subject). Try to get some photos if you can.

How long have you had the tank set up?

Sorry, I'm not having a go at you. It sounds like the shop has given you some awful advice. Stick with us and you'll soon know enough to run rings around your average pet shop employee, plus you've have happier, healthier pets.

Have a read here and compare that to the advice you got and how you were told to set up your tank. Please ask any questions!

 

[katetee]

Thank you for your advice so far. I have already looked in to getting a larger tank but as we are hoping to move in the next few months i thought it'd be easier to get it then. It is the test strips i am using which is why i said it my 1st post all the reading were within normal limits apart from the ph level which according to that was too low. The amonia level was also 0. How come if the water is so poor the other fish seem to be thriving, including the other discus?
I have no idea what sex the mollies are! i will try an upload a photo when i can.
As for the barbs i was originally sold 2 when i 1st got the tank last august, but one died a couple of weeks later.
Thanks again for the advice.

 

[GAB99]

test strips are usually inaccurate unless kept in very good conditions and even then tend to misread things.
alot of people recomend the API test kit, i use it and the results never go off as i test twice.

 

[Assaye]

Thank you for your advice so far. I have already looked in to getting a larger tank but as we are hoping to move in the next few months i thought it'd be easier to get it then. It is the test strips i am using which is why i said it my 1st post all the reading were within normal limits apart from the ph level which according to that was too low. The amonia level was also 0. How come if the water is so poor the other fish seem to be thriving, including the other discus?
I have no idea what sex the mollies are! i will try an upload a photo when i can.
As for the barbs i was originally sold 2 when i 1st got the tank last august, but one died a couple of weeks later.
Thanks again for the advice.

Those strips are not accurate enough for fragile fish and they tend to give very generic (and often unreliable) advice about what "good" readings are.

As for why the fish seem fine - they don't, one died. Even if other fish seem OK, a dead fish is a dead give away that something isn't right. In the wild a weak fish is a dead fish, because it would be very likely to get predated upon by larger fish. So even rather unwell fish are very well adapted to see Ok until they are too ill to save. It's also very hard to tell if fish are Ok because we're not fish. Unless someone is really quite experienced with fish they tend to miss the subtle signs that something isn't OK with the tank. As well as that, some of the damage done by poor water conditions is gradual. In the case of nitrite poisoning, the fish will behave normally until the damage gets so bad that they just stop working internally. It's like smoking - many people smoke for years and look fine but suddenly they might start getting sick because their body just can't function any more with all the damage they have done.

In short, testing with a reliable test kit and maintaining perfect water is the best method of keeping the fish safe. It prevents problems occuring and when they do occur, it makes it easier to treat the problem (such as an illness) without poor water stressing the fish further. it's always better to prevent problems rather than just react when something is already wrong - it saves the fish a lot of suffering and helps keep your workload down.

As I said, have a good read of that link. It'll explain the details of the nitrogen cycle and why these chemicals are bad for the fish and will give you good advice on how to stop these problems occuring.

If your tank has been set up for nearly a year you shouldn't be seeing nitrite at all as the bacteria in the filter should be plentiful enough to deal with it.

Do you ever wash/replace the filter media, and if you do, how do you do it? And do you use a tap water conditioner? Which do you use?