Dwarf Neon Rainbowfish Dead Help

[cooledwhip]

I tested my water and ammonia, Nitrate/trite was all 0 or at least under .25. I've had my rainbowfish for about a month or two now.
 
Tank setup:
20 gallon long
7 threadfin rainbowfish
3 dwarf neon rainbowfish, 2 males 1 female
 
About a week or two ago I have been seeing this tube coming out of my female rainbowfish. It as kinda by the anal fin and under the poopoo hole. She always strayed away from everyone and looked very small and thin compared to all the other rainbows.
 
Today I found her on the ground moving, like she was trying to swim but couldn't. I scooped her up and put her in a plastic breeder box and soon after she died.
 
What do you think was the cause of this? I will upload some pics. The males are all twice as large as she is.

 

[Munroco]

Some fish just aren't as healthy as others. In the wild survival of the fittest will weed out the weaker ones, while tank bred fish can survive. It's sometimes difficult in pet stores to pick out the more robust fish if you are buying a small school, especially with smaller fish. All things being equal I always try to get the bigger healthier looking fish.

 

[gmc1]

Was it nitrite or nitrate that was under.25?

 

[cooledwhip]

I bought these three online. The other two are some of the healthiest and most active fish I've seen. I guess this was the runt of the litter. I felt it when it was dead and it was all bony, really small. I'm guessing it couldn't get the food fast enough.
 
Nitrate and nitrite were both under .25 I think. Idk the exact measurements but they were 0-(lowest increment #)

 

[Munroco]

I have 6 American flag fish, there were only 6 in the LFS and two of the females were really hollow bellied. I suggested they give me these two free.
 
One of them is slowly getting more rounded but the other looks as bad as when I got her. She is always looking for food and I've been more or less hand feeding her but she doesn't put on weight. I've had them for about six weeks and each day I expect to see her floating but she keeps hanging on. I feel really sorry for her but can't think what else to do.

 

[gretakarol]

I'm pretty sure I know what this is. Look up "dropsy" online. It is very contagious and you may want to change your water extra frequently. Sometimes they suggest euthanizing the other fish swimming with it too.

I had to go through this very sad process. Good luck.


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