Swordtails Dying.

I have a 60 gallon community tank, properly established for around 3-4 months and there are healthy(apparently) swordtails along with other peaceful species. They are dying one by one. I've got 4 dead in the past 1 month. I also got 2 fry born 2 weeks back. Nitrates are 6 ppm, PH, GH, Ammonia, Nitrites all ok. No spots, redness or any identifiable physical or activity change. I feed them pellets, flakes, live bloodworms, brine shrimp. No other species seems to be affected. Only the swordtails. Male-female ratio is 1:3. I can think only of overfeeding, bacterial infection (possibly through bloodworms), maybe bad batch with low immunity or something. All of them were okay initially. One female had one or two pea sized discoloration spots. It was probably the one which gave birth. Not sure. Please help me find the cause and remedy for it. Thanks.

 

Sorry to read about your fish. Can you give us a little more information like the actual numbers for pH, GH, ammonia and nitrites? Telling us they're ok doesn't exactly help. Can you also give us a list of the other inhabitants and how many you have?

 

pH I've kept at around 7, temp 24, Hardness around 10-11 dGH Ammonia 0 Nitrites <0.01. 6 female swordtail, 2 males, 8 serpae tetra, 6 zebra danios. Swordtails are the largest in size. Others are not even adults yet, have not noticed any bullying or aggression except male swordtails chasing females.

 

Numbers seem ok. What test kit are you using?

How long have you had the swordtails? Any new additions?

 

API Freshwater ones.. I've had them since the beginning(between 3 and 4 months, not including the cycling time). Nope no new additions lately.

 

Not sure then... my initial guess would have been the hardness of the water but your GH is at a pretty good level for them. I'm hoping you don't lose any more.

 

I had a batch all die on me with perfect parameters. I figured it was the batch I purchased.