Disease disease disease and death :(

Question
40 Gallon. cycled fully for 3 months, (was previously a 20 gallon fully cycled)



Levels: 0 Ammonia (API drops) 0 Nitrite (API Drops)  Approx. 12.5-20 Nitrate (Tetra Test)

(subnote:....I just did a 40% ish water change to slightly lower the Nitrate just in case)

Fish:  5 Guppies (all male), 2 Black Mollies (1 Male 1 Female) 1 Lyretail Dalmation Molly,(female) 2 Glass Catfish (unknown lol) 2 Harlquin Rasbora, (unknown) 2 Cherry Barbs, (unknown) 2 Neon Tetra, (unknown) 1 Angelfish (no it doesn't bother with the little neons, got them all as babies and they have grown together... unknown sex as well) 1 Flower Shrimp



Problem:  Crazy unknown and known multiple diseases, 2 guppies have died in the past 2 months and all of my Mollies, 1 glass cat and 1 guppy starting to show signs are on their way out



History:  Male Black Molly showed signs of fungus (fin rot, cotton mouth and cotton like patches), treated entire tank with API Fungus cure, everything cleared up and no more effects were noticed until I added 1 fancy tailed male guppy from my local Fish Store......with in 2 weeks the guppy died.  Unknown reasons, no signs of fungus or bacteria, just started swimming vertical head up and later died on the bottom of the tank.

2 weeks after that I added the existing Rasboras, Cherry Barb and Neon Tetra (made sure levels were all 0, 0, and 12.5 before I did so)  They lasted and are still ok.  Week or so Female Black Molly showed signs of Fungus, same cotton like problems as the male from last time.  Treated for fungus again, fungus cleared all was fine again. Last week I added a Green Variated Type gupppy and the flower shrimp and within 2 days the guppy started showing signs of Tetrahymena (white band parasite) and before I realized what it was he too passed away.  I have a good friend at the local fish store and she gave me a 4 tablet dose of Clout (my tanks is 40 gallons)to try to clear whatever is constantly growning in my tank........while the guppy died, my 3 mollies, 1 other guppy, 1 glass catfish, and 1 Rasbora began to smash themselves off the bottom of the tank and the tank walls for no apparent reason. (the 1 glass cat in question has its whiskers pointing back to his body so I know something is up) The Male Black Molly is practically dead, almost laying lifeless on the bottom slightly tilted, my female black is following suit, the dalmation has tiny redspots in between her normal patches of black and white and she too is slowing down as well spending more time on the bottom.



I don't notice any signs of Ick, my temperature is always at 81, I do a once a week water change (25%) week 1 syphon gravel, week 2 water only,  week 3 rinse filter media in filtered tank water, week 4 water only....etc

I only introduce fish if there are no signs of stress or tank problems, and I never add new fish until the tank has stablized from the previous add. I have stopped adding anything now till I figuer out whats going on.



Any ideas why I keep getting diseases, what is going wrong with my tank now, why are they smashing themselves insanely, and what else can I do to clean it all up.

(I also have a bubbler and the water level is about 2 inches below the rim to add extra oxygen)



Thank-you for your time  

Answer
Hi Tamera;

They are scratching from irritation, either from the medication or infection itself. Many different problems can cause that and since we can rule out ammonia poisoning, I suspect the meds or infection. You might want to make a 25% water change to reduce the clout concentration in case that's what is bothering them. While Clout is very effective, it can be very harsh on the fish and it can also kill your shrimp. Try to separate him to a clean isolation tank or a jar with an airstone or something if he has survived so far.

The disease they have been fighting could be protozoan and/or bacterial in my opinion. The two possibilities I suspect are (one you know already); Tetrahymena corlissi (protozoan) as well as Flexibacter Columnaris (bacterium, commonly mistaken for fungus). The clout should treat the Tetrahymena but you need a different medication if Columnaris is involved. Here is more information about columnaris and how to treat it;

http://network.bestfriends.org/groups/friends_of_fish/news/archive/2006/06/23/pr...

Your maintenance is great but I think you are introducing disease with new fish, probably the guppies. Guppies these days are just not the sturdy old standards they used to be. They are often severely inbred and weak, as well as not being treated very well after they leave the breeder or fish farm where they grew up. Fish become stressed when in transport to your local store, and sometimes the culprit for creating stress is the store itself. If the fish already tend to be weak, they get sick easily from pathogens that exist everywhere. Healthy fish with strong immunity that aren't under stress (your established fish) don't normally get sick unless sick fish are introduced to your tank and bring with them large numbers of the infectious pathogens. You don't always see the illness or parasite until they have been in your tank a few days and it gets worse. Quarantine tanks are a good idea for that reason. Keep new fish isolated for ten days to two weeks. Keep their water very clean so they can be observed for illness and hopefully they will be able to join the main tank inhabitants. Medication isn't necessary unless you actually see serious disease that needs it.

I hope they do okay...

At Your Service;
Chris Robbins