Fish dying without warning!

[flassdaddy]

OK I am not sure what is going on I have lost 3 fish now in the last month suddenly with no warning. First I lost Cremecicle Lyretail Molly, then a Zebra Danio, and now today my silver tipped shark. They all appeared fine one day and then dead the next with no warning, except for the molly, she was obviously sick before she died. She didn't swim and just sat on the bottom but between first signs and death was only 8 hours or so. Besides that she had no other physical signs of and the other fish gave no warning at all. Here is the tank info.

29 Gal
80 Degrees
PH 7.0
Ammonia 0
Nitrites 0
Nitrates 10

Filter - Aquatech 30 (Getting a new filter soon) & a Wishper 3 gallon internal filter that I use for aeration and some extra carbon.

There are now 3 Zebra Danios, 2 Cremecicle Lyretail Mollys, 2 Blue Gourami, and a Chinese Algee Eater in the tank. The tank has been up since the beginning of November and most of the fish have been in there since mid December. I do a 30%-40% water change every 10 days or so and I have been feeding them TetraMin Tropical flakes.

If any one has any ideas or advice it would be greatly appreciated. Thanks.

 

[talloulou]

Your ammonia reading should be a definite 0 so check in to that and make sure it is. When you change the water you add a dechlorinator right? Its a good idea to feed your fish a varied diet vs one type of food only......though I doubt that would have killed them this early on. Did you use any chemicals in the tank? Try to treat any disease or alter the pH or anything? Did you add any new decorations? Did any of the fish show signs of being picked on?

The mollies should be kept with 1 male to thee females so none of them get tortured.
Danios are pretty hardy hard to kill fish so I'm not sure what's going on. If your ammonia is really 0 maybe you just had a bit of bad luck? I would keep cleaning the tank like you have been and wait a good while before adding anything new to see what happens.

 

[flassdaddy]

The ammonia has been 0 for over a month now those readings are from today. I treat for an entire tank when I change the water and nothing has been added or altered since I have set it up. I haven't added any chemicals and everything has been stable since it finished cycling. The fish that are in there all appear to be very happy. There is now 1 male molly and 1 female. I have never seen any of the fish be aggressive except for the Gourami's who get aggressive with each other occasionally.

Thanks for the reply.

 

[flassdaddy]

Corection: I add 15ml of stress enzyme every time I do a water change.

 

[Devilishturtles]

Sounds like you are doing everything correctly. Sometimes fish just die with no outward reason why. Likely not your fault either. I wish I had a suggestion, but cannot think of anything on top of what tallloulou already asked you.

Sorry about your losses.