Sick Yellow GloFish & Nitrite Problem - Need Advice

Cyanide

I have a tank of four zebra danios, one being a Yellow GloFish. As of the last two days or so, he's been looking pretty sickly. He only swims to the top left and right parts of the tank, and seems to stay there all day - he never socializes with the other fish. The other three regular zebra danios swim about the tank, eat voraciously, and generally look good - not my yellow one. He also seems to be very thin - I tried to feed him extra, but he refused to even eat the tiniest bit. I tested the water, and my nitrite ion level is through the roof - the strip pad is bright pink. Are my plants affecting this crazy shootup of nitrite, or is it okay, and just the fish is sick? What do you recommend I do?

If I need to remove Mellow Yellow (my parents renamed him xD), then I can do so, but I don't have an isolation tank. Hope he doesn't die!

iamntbatman

Do a big water change ASAP. I'm talking like 60-70% right now. Nitrite is extremely toxic to fish so high nitrite levels are a big problem. Luckily zebra danios are extremely hardy but this is no reason to keep them in such conditions.

Next, get yourself a good liquid test kit. The paper strips aren't very accurate and the liquid kit ends up being less expensive over the long run as it's much cheaper per test than the strips. Get good readings for ammonia, nitrite and nitrate. Any reading for ammonia or nitrite above zero is bad; do water changes until these are below 0.25ppm.

Plants can only be a good thing, so don't worry about those having any sort of negative impact (unless they're all dead and rotting, or something).

How long has this tank been set up? Did you cycle it before you added fish?

Cyanide

The tank has been set up for about a month, and nothing like this has happened - I had like NO ammonia or anything . Alright, I've got water set up, and I'm going to do a major water change. It's just so weird - Mellow Yellow's the ONLY one acting weird and not eating - the other three are normal and super happy. o.o" However, I did notice my peacock plant thing sort of changing shades - it looks like a different shade of green. Can't tell if that's growth or decay! Do you know? Thanks for the tip, iamntbatman! :D

iamntbatman

The bacteria that convert nitrite to nitrate reproduce at a much slower rate than the bacteria that convert ammonia to nitrite, so it's possible to have a nitrite spike like you're seeing without having seen an ammonia spike before it. I'd be willing to bet that your ammonia spike went unnoticed and you're just now seeing the nitrite spike in the aquarium cycle.

I've never heard anything about GloFish being particularly more susceptible to nitrite poisoning than regular zebra danios, so it could just be that he was weakened previously or something like that. Keep us updating on his condition though; hopefully it will improve along with your water quality.

Is it possible to post a picture of your plants? That'd be much easier to respond to than just a description of its condition.

Cyanide

Ok, just did a major water change - no immediate results. Will look for dead fish/retest tomorrow morning.

Cyanide

I'll try to post a picture of the plant - let me see if I've got a good camera....

Mean Harri

In looking at your aquarium info tab your water temp is about 7 degrees too cold at minimum. You are housing tropical fish. The water temp needs to be higher that 70 F. Turn it up a couple degrees and wait so as to slowly increase it to at least 77 degrees.
Secondly, you have 4 fish in a 2 gallon tank. You're about limit there pal if not over. In that small of a tank you may be over feeding and putting the hurts on mr glo fish because it's such a small tank.
Good luck mate

Cyanide

:( My heater doesn't work well - if I leave it on (it doesn't have a dial), it goes up to 85 degrees. The guy said that since I have 2.4 gal tank, I could house about 5-6 zebra danio max. Maybe he was wrong...I feed them just enough that they eat it all (very small pieces), but you could be right - maybe he just feels stressed with his hyper tank mates.

iamntbatman

I didn't know the tank was so small. Danios need a lot of swimming space as they're very active fish. The sooner you can upgrade to something bigger, the better off they'll be.

They should be just fine at 70*F. Danios come from colder waters than most tropical fish, so standard tropical temperatures are actually at the upper end of their tolerance.

Cyanide

Okay, I changed the water significantly, and Yellow ate a teeny bit for breakfast, and is now swimming around with his other tankmates. The nitrite level is much lower now, too, but I have a feeling Mellow Yellow's gonna die - he's so gaunt (thin) compared to the other fish! I will try to get a bigger tank soon (maybe for my birthday?)