Fish dying 1 by 1, erratic swimming only sign

[contactpsb]

Over the past 4-5 weeks, my freshwater tank population has been cut almost in half. I bought some new fish at my LFS and didn't QT. A few days later, 3 of the new barbs were dead. Since then we have been losing fish here and there for no apparent reason. No physical signs of disease, all water parameters are normal. We lost about 8 barbs, my big rainbow and albino sharks, my 2 male Mollies, and a dwarf guarami.

The only thing I have noticed is that when a fish is apparently affected, he starts swimming very erratically, sort of blowing around the tank in circles, upside down, randomly. Then he may straighten up and swim right for a minute and back to the crazy behaviour. Usually it only takes 10-20minutes after I notice this for them to expire.

I had two freshwater tanks, a 55gal and a 75gal, and after losing fish from both (we added new fish to both so both tanks seem to have gotten the same disease or whatever) we decided to just combine them all into the 55gal and take this opportunity to drain and clean the 75gal before we restock.

I'm at my wits end, don't know what to do to treat the tank. Any suggestions of what it might be or what I can do?

 

[Menagerie]

Try looking through these sites:
http://www.aquatronicsonline.com/hobbyist/hobbyist3.htm
http://www.aqualink.com/disease/sdisease.html#ich
http://fish.mongabay.com/diseases.htm
http://www.wetwebmedia.com/AqBizSubWebIndex/fishdisho.htm
http://www.fishpondinfo.com/health.htm

Right now, I'm not sure. Perhaps a swimbladder disorder.

 

[contactpsb]

Well I'm at a lost for what to do. I am watching two fish now (1 barb and 1 guarami) as they swim in circles. The barb has been at it for over an hour and is going upside down, etc. I just noticed the guarami swimming in circles a second ago so he's probably not far behind.

One of the disease charts listed "Whirling or Spinning" as a symptom of Myxobacterlosis, which definitely applies, but also lists "Lumps on the body, Discoloration, Black Pigment on Fish" which I have seen none of.

Another one says "Unexplained fish loss, No outward signs or symptoms" could be Hexamitosis or Octomitus. Both each of these diseases lists like 5 medications, I don't know if I'm supposed to use them all, or if they all treat the same thing and I'm just supposed to pick one, or what.

 

[Menagerie]

Hex-A-Mit is the only med mentioned in both descriptions--I would treat the tank with that. Personally, I have never used Hex-A-Mit, but you are loosing fish and it's time to take action.
From http://www.thatpetplace.com/Product...es+Medications/T1/F62+0001+0054/Itemdy00.aspx :

Hex-A-Mit is a colorless antibiotic used for freshwater and marine aquariums. It is an aid for the treatment and prevention of Parasite Protozoans, Hexamita, Discus and Angel Disease, Unexplained Death, Holes in the Head, Freshwater Velvet and Cryptocaryon irritations. This treatment is specific for Angels, Discus, Tetras, Corydoras, Plecostomus and all Marine Fish. Hex-A-Mit used as directed is safe in the community tank and will not affect biological filter beds. Do not use with invertebrates.

Instructions:
Use Hex-A-Mit as directed. Carbon should be removed from the filter during treatment. Do a partial water change before and after treatment. Shieldex may be used before and after the treatment. Carbon-It may be used if undesired chemicals or antibiotics are present in the water. Filter the water first with Carbon-It for 3 to 4 hours then do a partial water change. Treatment in a quarantine tank is suggested unless infections shared by several fish. Hex-A-Mit can be removed from tank water by adding carbon to the filter.

Open capsules and introduce powder directly into the aquarium. Use 1 capsule to each 10 gallons of aquarium water. Treat every other day for 5 days (3 treatments are suggested). If necessary repeat full treatment in 3 days. Double dose in marine aquariums. Do not use with invertebrates.

Ingredients:
250mg Capsules of Water Soluble, Metronidazole Activity.

Good luck and keep us updated.

 

[Bearfan]

What kind of oxygen supply do you have to the tank?

Sounds a little like suffocation.

 

[contactpsb]

Well we have an air pump with two 9inch airstone bars in the tank now, but when we had the 75gal up and running it also had two 9inch airstone bars and two additional mini airstone inside decorations. My fiance is the bubble king LOL I think it's too much but he likes it. Is this enough or not enough?

 

[snapcrackler]

Did you make sure you're not having a spike of some kind? maybe they are getting nitrite or ammonia poisoning? Sounds like they are dying fast.

Usually with ammonia or nitrate poisoning the fish will hang out near the surface and gasp and stuff though which you didn't mention. Never hurts to check the water though...

 

[Bearfan]

Well we have an air pump with two 9inch airstone bars in the tank now, but when we had the 75gal up and running it also had two 9inch airstone bars and two additional mini airstone inside decorations. My fiance is the bubble king LOL I think it's too much but he likes it. Is this enough or not enough?

More than enough...don't know that there is a too much level unless it is a planted tank. Suffocation isn't it.

 

[contactpsb]

Update - We went to the LFS and had our water tested, and everything was normal except the PH was really low, it was like 6.0. They recommended doing several water changes over the next few days to raise it gradually, and we are treating the tank with Kanacyn which she said was a broad spectrum antibiotic since we don't know exactly what the problem is.