Sick GloFish/Danios (Won’t eat and lethargic)

[ChemEngineer]

As the title mentioned, my danios are having some issues. I recently got back from a trip of 4 days during which I used a 10 day feeder. Upon my arrival back home, I noticed the danios were acting kind of sluggish, but I went to bed thinking that they were perhaps just hungry. The next morning I woke up to find one of my glofish dead (one that replaced a glofish I bought from the local fish store that had died within a day, a.k.a two dead fish in a week), and the remaining 10 danios all at the surface, but not moving too much. Some of them are at an odd angle of 45 degrees to the surface of the water. I tried feeding them, but they just watched the food go by them instead of their normal feeding frenzy they go through. I want to also point out that none of them are gasping at the surface.


I immediately tested my water and found the following… (I used the API Freshwater Master Kit)


Ammonia – 0-0.25 ppm
Nitrite – 0 ppm
Nitrate – 20-40 ppm (High but not obscenely high)
pH – 7.8


I then did 30% water change (I normally do a 20% water change once a week), and added 2 doses worth of Seachem’s Prime. The nitrates dropped somewhat, but still not below 20 ppm. The danios then started to move around a bit more and seemed to swim more normally.
Move forward one day!


I woke up this morning and the danios were once again at the surface refusing to eat. They still are not gasping for air. Any ideas of what is wrong with them? I was thinking perhaps the nitrates were still high so I did another 30% water change.
This is what is strange though…


My tank is a 29 gallon oceanic biocube with the standard lights and pump (243 gph). The tank is housed with the following: 11 (now 10) danios, 1 dwarf gourami, 2 peppered cory catfish, 2 oto cats, 3 amano shrimp, and 2 german blue rams. I realize this is overstocked, but the fish are not harassing each other at all, and I have not had any problems until recently. The tank has been set up since March of 2011, and fish were added only in groups of 2 or 3 at a time. Also, the tank has driftwood and live plants in it. The live plants seem to be thriving despite having no CO2 injection, and just a weekly fertilizer dose.


The strange thing? If the problem were nitrates, why are my ‘hardy’ danios being afflicted, but my ‘fragile’ oto cats and german blue rams still eating normally and showing no unusual signs/symptoms?


Thanks for any help you guys can give; and my fish thank you even more!

 

[librarygirl]

I'm still new at this hobby so I won't even attempt to guess at your issue since the basics seem to be ruled out (the tank seems cycled, no high levels of ammonia, etc). At least my reply will bump this up and hopefully someone else can help.

Good luck, and sorry about your fish!

 

[alLexX]

probably overfed on the feeder,and the rams were too shy to get close enough to eat.and the ottos wouldnt touch it.

 

[jpchin]

i would worry more about the ammonia than the nitrates. the ammonia should read 0. my suggestion would be to clean your gravel (not all 1/4-1/2) you might have decaying food since it was a self feeder. i would do 25-30% water changes everyday until your ammonia returns to 0. also clean gravel every week. if you have live plants make sure they are all in good shape. no rotting. since you are overstocked, water changes should be every 3rd day or so. imo nothing beats fresh water to keep fish healthy. i do one every 3rd day and i'm not overstocked. good luck.

 

[ChemEngineer]

Just an update...and thanks for the responses!

I have done another water change, and the stats are all better. The ammonia is nearly 0, nitrite is 0, and the nitrates are between 10-20 ppm. However, the only comment I have about ammonia being "high" was that if it were high, why wouldn't my rams and ottos be dead already? Also, the danios are still behaving pretty much the same...just slightly more active.

As far as the danios overfeeding on the vacation feeder goes, how long do you think it would take for them to regain normal behavior? Is there anything I can do to help, besides not feeding them?

 

[jpchin]

ammonia can go up to 8.0 on the test card and probably higher than that so .25 isn't high enough to kill the fish but they can suffer from ammonia poisoning at anything over 0 basically. the ideal is 0 and what you should aim for. the water changes will help but i would also do a gravel cleaning of at least 1/3 of the gravel surface. make sure to put the cleaning tube into the gravel to remove hidden dirt and waste. not just on the surface of the gravel. doing that and making the water changes should get you back on track. i would feed my fish lightly once a day while you are doing the other things. keep us up to date on your progress. your nitrates are great. i don't know how long it will take for the danios to act normal but they should come around.