Tank worries...

[firbyster]

Hello everyone,

I am a bit worried about my tank. Before I go any further, here is what I have: 30 gallon freshwater tank, fully cycled.
I added fish to the tank about three weeks ago, 2 black mollies, 4 (now 3) red sailfin mollies, 4 guppies, 5 tetras, 2 catfish.
The water has been consistently good with readings of: ammonia 0, Nitrites 0, Nitrates 20 mg/l
Here is why I'm worried. About a week ago one of my sailfin mollies started swimming a bit funny, I noticed he wasn't using his top fin (a clamped fin). After a few days of swimming like this, I noticed him resting a lot at the bottom of the tank, hiding beside a rock. And as of this morning he passed away.
My concern is that there is a disease or something in the tank. I say this because I've noticed a few of the fish with some white stringy poop. The thing is, it's mixed with normal poop. So I can't say for sure if this is an internal parasite or if it's digestive problems. None of the fish are bloated, or losing weight and seem to be doing fine.
Anyways, if anyone has any input or ideas about what may or may not be going on it would be greatly appreciated!

Thanks in advance for any help!

 

[Greendragon1128]

This sounds like what I called the "platy plague." I found this website that has a page of all kinds of fish diseases.

Fish Disease and Treatment

I decided the "platy plague" is most likely chilodenella or hexamita. It seems to be gone from my tank, but I'm still doing frequent water changes to get rid of the protozoa that cause these diseases. If any of your fish start swimming strangely, put them in a hospital tank and do a water change.

 

[firbyster]

Thanks for the reply!

I suspected it may be hexamita.... I just read that this is something that won't go away unless treated with something like metronidazole... The thing is, the fish seem okay, but still a bit of white stringy poop. Should I treat my tank with this stuff as a precaution? Will this affect my fish if they are infact healthy??

Thanks!

 

[Greendragon1128]

Yes, treat the tank. I read on that website that the symptoms don't show up right away.
I found a medicine that treats ich and many other diseases, and I'm seeing if it will work. I thought the disease was gone, but then my female swordtail started swimming strangely, and now one of my platies is sick, too. It never goes away!
Good luck!