Laith

One of my three discus has been breathing very rapidly for several days. Almost like taking big gulps of water and forcing it through its gills. He's not hanging out at the surface but midwater...

I've had these discus for over a year now with no problems, no new additions to the tank.

I have been dosing using the EI method and am wondering if the Nitrates are very high? would this induce this type of reaction?

If so, wouldn't other fish exhibit the same thing? at least the other discus?

Very strange...

Osteomata

I know very little about discus, but hanging out on these forums I have seen a number of requests for help with sick fish. Invariably, the experienced aquariasts on here want to know a bit more info than you have provided, such as:
What are your CURRENT parameters, especially pH, temp, Ammonia, Nitrite, and Nitrate. I suspect kH would be helpful too so as to calculate CO2. Are these parameters different than say a week ago?
What was the last significant thing you did to the tank before noticing the symptoms? How recently did you do the EI 50% water change? How recently did you add ferts, and how much did you add. Stuff like that.
How long have you had this fish in this tank? Same with his tank mates?

JanS

High nitrates could certainly be one cause.
Try another big water change, and see if that helps at all.

If you can post the other things that Osteomata mentioned, that would help us give you more specific answers as well.

Laith

200l tank
2.4wpg
pressurized CO2
KH=6
GH=11
pH=6.75
NH3/4, NO2 =0
NO3=20-30
Temp= 27-28C
PO4=1.5
Fe=0.3

The Nitrate reading is suspect because the kit does not calibrate with a known solution. The above is an estimate based on my dosing and assumed uptake.

I realized that high Nitrites (NO2) can cause heavy breathing symptoms due to reduce O2 absorption but was not aware that Nitrates (NO3) can also give the same symptoms...

No new addition to tank. Slight increase of CO2 (+10-15mg/l) about three weeks ago at the same time as I started dosing using EI method.

Laith

And I'm dosing 10mg/l NO3 3x a week, 0.6mg/l PO4 3x a week, 0.1mg/l Fe 3x a week. And 7.7mg/l of K and 6-7mg/l of Mg at water change.

Gomer

Assuming everything is idea (ie nothing messing with the pH Scale and all your test kits work perfectly), the onlything that is a flag is your CO2...which might be a bit high. Try backing it down a little and see if that solves the problem.

shalu

Don't think high NO3 is directly responsible for it. I don't see why you need to dose 10ppm x3 per week, I would cut it to 5ppm x3 anyway.

Is heavy breathing going on also in photo period? If so, then no O2 problem. Lack of O2 would affect other fish as well. Gill fluke? possible. But try do more water change and see if it improves first.

Laith

hhmmm... CO2 too high? I know it's a bit above normal but it's only at around 36-37mg/l. Maybe I'll try to bring it down to around 25-30...

Regarding the NO3 dosage... Whenever Tom is recommending KNO3 dosing for a tank, he pretty consistently recommends around 1/2 a tsp 3x a week for a 50g (he's also said 1/4 tsp 3x a week per 20g, which is close). And I've seen this same recommendation for tanks whether they are at 2wpg or 4+ wpg.

I also have some reservations about this amount as it automatically assumes that NO3 uptake is high. I have asked whether one should change dosages depending on the wpg one has but never got an answer. I guess the assumption is that with big water changes every week it's a moot point?

It would be good to know exactly what type of symptoms fish will show when the NO3 gets too high. I haven't been able to find this info yet... However I have been getting very markable plant improvement since dosing this much!

And yes, the symptoms are there during the photo period as well as outside of it.

I also thought of gill fluke but where would he get it from? Is this a parasite that can be dormant in the tank until something triggers its activity?

No other fish are showing similar symptoms so I'm a bit stumped.

Appreciate the inputs!

shalu

I have dosed the tank to 20-30 ppm NO3 before without apparent problem. The reason I recommend less NO3 is that the general dosage recommendation is based on the assumption the tank is moderately stocked and a tank with well fed discus is usually beyond "moderately stocked". But high NO3 should not cause any problem.

My understanding is ALL discus carry SOME gill flukes. But infestation only occurs when the fish is under environmental stress.

TWood

In other words, you have no idea what the NO3 level really is.

Get a handle on the NO3 and the answer might arise.

TW