Please, Help!

[macdonald20]

Ok, first off I don't know the water parameters, but I will post when I know. I will give you the backround on the tank. Yesterday we had 12 fish in a 55 gallon tank. The tank has 2 filters but one of them has recently stopped working (we're working on it). The water temperature is 80 degrees. There is one large heater, a couple caves, a few plastic plants, and gravel. There is a red-tailed shark (female, 1-1/2 years), 2 guppies (1 male, 1 female, 6 months), 1 rosy barb (1 year), 3 rosy barbs (3 weeks), 5 tiger barbs (3 weeks). They get fed flake food and occasionally dried brine shrimp. They all seemed very healthy and active this morning. They were fed at 7:30. At 12:00 I checked on them (I usually do a headcount on the tigers) And there was one tiger barb stuck to the filter. I scooped it out imediately and noticed that it's eyes were white and the fins were shredded. I did another head count and they all looked healthy and active. Checked on them again at 2 and they were fine. They get fed again at 6:00. (unfortunatly I was not there to feed them, so I don't know how they were). I checked on them again at 9:00 and couldn't find another barb. While I was looking for it I noticed a dead fish on the bottom of the tank. Our poor little male guppy. The eyes were white, his tail and stomach were missing. Found the other barb when I was scooping out the guppy. Right now all other fish are doing fine. Is there something wrong with the tank? Or could one of the fish be doing this? My boyfriend thinks that it may be the shark, but she's never done anything like this before. She may be territorial, but she's never eaten fish. She's never even looked at a guppy before. Please help before I lose more fish (especially the older ones, I'm kind of attached)

 

[Twinklecaz]

What size is your tank? I know Tiger Barbs can be very nippy so I don't know if that have anything to do with it. Could be the Shark but I don't know a lot about them.

Could be the water quality too. What could be happening is the fish are dying and then the others are eating them afterwards. How long have you been set up?

 

[roadmaster]

How often and how much water do you change? Could you take a sample of water to local fish store and ask them if they will test it for ammonia,nitrites,and nitrAtes?
I might perform daily 20 percent water change with dechlorinator for new water until I could get the water tested.
If water tests = zero for ammonia and nitrites and nitrAtes are at 20 ppm or lower,then it could very well be that the shark is killing your fish or terrorizing them to the point that they become stressed which often leads to sick fish.
This is pure speculation but without knowing what the water test's reveal.. it's all anybody can do.

 

[Athena]

Does sound like your RTS is the culprit here. They can attack fish smaller than themselves, especially if they are hungry and lacking protein. They also become quite aggressive if they feel their territory has been invaded.

I see you've had your RTS a year and a half but you have other fish that have been put in a few weeks ago, is that right? This could have led to the sudden change in the temperament of your RTS. Even though they are all in a fair size tank, if the shark has been used to having more space to itself and now having to share with a few others, it might have stressed it enough to go on the rampage.

Also, try feeding a couple times per week with some frozen/freezedried bloodworms if you can get them.

As you've had a few fish deaths it's a good idea to do a partial water change, too, because a dead fish can quickly pollute the water and cause an ammonia spike the longer the dead fish is in the water.


Regards, Athena

 

[macdonald20]

This particular tank has been set up a little over a month. We bought it secondhand. They were in a little 20 gallon tank, ut it was just the shark, 2 rosy barbs, and 2 guppies. We added the rest of the fish after they were moved to the larger tank and one of the barbs died. So anyway, I tested the water last night and I got ammonia - 0, ph - 7.0, nitrate - 5, nitrite - 0.