Discus deaths

[KRUCIAN KING]

I have a 90 gallon and on Friday night I did a 50% water change, came home Saturday afternoon four of my discus were dead three others were laying on there sides gasping for air. I use prime, water temp at 84, here is what baffles me my water parameters ammonia 0 ppm, nitrate 5.0 and nitrate 80 ppm. What happen? I am so blown help

 

[Becca]

Is it possible you either filled the tank too high or forgot to dechlorinate?

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[Frank Cowherd]

A possible cause is lack of oxygen. This could be because the filter was plugged up and there was no or little water movement in the tank. Lack of sufficient oxygen can also result from a carbon dioxide tank/flow being too high. Under lack of oxygen cases, the fish that can survive are the ones that breath air, like corys and anabantoids.

IF the tank is planted, the lack of oxygen (water movement) is even more critical at night since plants consume oxygen when the lights are off.

 

[JLW]

Jerry, you have two different readings for your nitrate reported above. I'm assuming that the first one, at 5.0, is supposed to be nitrIte. 5.0 mg/L (PPM) is actually the maximum on the most common charts, and is really a very high level. While nitrIte isn't 100% lethal to fish, it is extraordinarily stressful. In a healthy, mature aquarium, nitrIte (and ammonia) should never appear at more than a trace.

A higher level indicates a breakdown in the biological filtration of the aquarium. This can be for several reasons. The most common is that the biological filter has not yet fully matured -- I don't know how old the tank is, and whether this is the case.

It could also be from a die off hitting the filter, such as if it was hit with chlorinated water (very unlikely), antibiotics, or other chemicals.

Lastly, and most likely with a mature tank, it indicates a huge influx of something toxic -- someone dumped a can of fish food or a bologna sandwich in the tank, or a fish died behind a rock and you didn't remove it. It can also come from your source water, if -- for instance -- your tap water has chloramine rather than chlorine, and the prime dose was sufficient to break the bond between chlorine and ammonia, but not neutralise the ammonia. (Chloramine is a combined chlorine and ammonia dosage. It's used to sterlise our drinking water, and is more stable and effective than just chlorine. It's also more toxic to fish. When dosed with a sodium thiosulphate based dechlorinator, such as prime, the dechlor first breaks the chloramine into chlorine and ammonia, and neutralises the chlorine ion. This takes about twice the amount of dechlor as just chlorine does, but your "usual dose" is typically enough to do this anyhow. The ammonia is then free to wreak havoc in the tank. Most dechlorinators will also neutralise ammonia, but take a heavy dose to do it -- you want to use a double dose of prime if you've got chloramine).

It's also possible that your Prime has neutralised any ammonia, and it is testing as zero. Another huge dose of prime will help with the nitrite, too. Also keep in mind that if you are having an ammonia problem that is not being detected, if your brought your pH up with the water change, you increased the toxicity of the ammonia (and a big change in pH can really mess up discus anyhow).

Assuming this isn't a typo or some such, I think it's your culprit. I'd try to find your source of nitrite, and eliminate it. Its possible its the tap.

 

[Jmty]

aged water will avoid all this guessing ?

 

[YSS]

Nitrate reading seems pretty high as well. Most discus keepers try to keep the nitrate level to below 10ppm. How long has the tank been up and running with discus?

 

[KRUCIAN KING]

Thanks guys for the advice, the tank has be up for about a year. Well I cleaned out the tank yesterday and started a new cycle. The remaining discus are in my main tank housed with my angels which don't seem to thrilled about the new living arrangements.

 

[Termato]

Great information JLW. I was able to find a little bit more on the effects of prime on testings. Here is what I found on their website:

"Prime works by removing chlorine from the water and then binds with ammonia until it can be consumed by your biological filtration (chloramine minus chlorine = ammonia). The bond is not reversible and ammonia is still available for your bacteria to consume. Prime will not halt your cycling process.
"I am going to assume that you were using a liquid based reagent test kit (Nessler based, silica). Any type of reducing agent or ammonia binder (dechlorinators, etc) will give you a false positive. You can avoid this by using our Multitest Ammonia kit (not affected by reducing agents) or you can wait to test, Prime dissipates from your system within 24 hours."

With most kits which test for total ammonia, (like the API test kit) you will get an accurate total ammonia reading but not an accurate free (toxic) ammonia reading. What this means is that it will not tell you is the ammonia has be detoxified. Prime works to detoxify ammonia by binding the ammonia and holding it in a non-toxic state for about 48 hours....

Any ammonia, nitrite, or nitrate which has been detoxified will usually stay bound for about 48 hours.

Seachem Prime and false positives