Random And Sudden Death

[vthokie]

Hello all,

I have 5, now 4, Rainbowfish (Melanotaenia praecox) in a 29 gallon tank with 3 blue-tail tetra, a bull shark, a pleco, a betta, and a dwarf gourami. I have a hanging power filter (with bio), heater, and all the usual treatments. My water is very hard and the pH is >8. I have had the tank for nearly a month.

Recently I stopped feeding them twice a day and moved to once in the evening. I noticed that they didn't eat all the flake and thought that once a day would be adequate. Yesterday I was feeding them and like usual the rainbowfish and tetras swam to the top in a frenzy to eat. I noticed a rainbow fish suddenly dart down to the bottom, turn inverted, and slowly float to the top respirating heavily. It bumped into a floating plant and darted into the sides of the tank until it came to a rest at the bottom corner of the tank, not really moving. I thought it was dead, but a few hours later noticed all 5 rainbow fish schooling as normal.

Today I was feeding the fish, and in a similar manner they came darting to the top, the same rainbow fish darted to the bottom and then to the top, turned a really dark shade of grey, and just died.

What happened? I can take a pic if necessary.

Thanks!

 

[WILDER]

Sounds like bad water quality due to a cycling tank, do an immediate water change, plus increase aeration in the tank, you have added to many fish to soon to a new tank, you should only start off with a few hardy fish till the cycle has completed.
I would research the bull shark as i've never heard of it.
Plus if you don't have a test kit invest in one the liquid ones are the best, Ammonia, nitrite, nitrate, and ph. for now take a sample of the tank water to the lfs and tell them to write the readings down for you, then get back to the board.

I woulod get a pic up of the shark as a bull shark, well do the search for your self, what does it look like, do you mean a bala shark.

 

[vthokie]

Sounds like bad water quality due to a cycling tank, do an immediate water change, plus increase aeration in the tank, you have added to many fish to soon to a new tank, you should only start off with a few hardy fish till the cycle has completed.
I would research the bull shark as i've never heard of it.
Plus if you don't have a test kit invest in one the liquid ones are the best, Ammonia, nitrite, nitrate, and ph. for now take a sample of the tank water to the lfs and tell them to write the readings down for you, then get back to the board.

I woulod get a pic up of the shark as a bull shark, well do the search for your self, what does it look like, do you mean a bala shark.

Thanks for the reply. The "bull shark" is also called a black-fin catfish. I have been progressively losing fish (2 blue fin tetras developed swollen guts and became listless..eventually died)

I have a strip tank tester, and I just did a cleaning with a siphon (50% of the water).

The nitrates dropped, but they are still in "stress" zone.

Why would that particular rainbow act like that and just suddenly die? It was very strange.

 

[vthokie]

I also noticed that in one oif your posts you say that a darkening in color is a sign of bacterial infection. The fish turned from a silver to mid-grey almost instantly after death.

 

[WILDER]

Do you mean nitrites instead of nitrates, you added to many fish to soon to the tank.
Swollen bellys can be constipation through a bad diet, swim bladder due to poor water quality and bad diet, can't maintain there balance in the water, plus dropsy swollen belly with prutuding scales.
A good varied diet is just as iimportant as water quality, need frozen foods and veg in there diet.

Look under feeding.
http/www.skepticalaquarist.com/docs/health/viruses.shtml

Also look at beginners section.
http/www.fishforums.net/index.php?showforum=58

 

[WILDER]

Well fish can go to all sorts of colours after death so i wouldnt read much into that.
More interested in your stats in ammonia,nitrite,nitrate,and ph.When fish are in bad water quality it takes it's toll on them causing desease, as bad water quality can cause there immune system to shut down causing death as they cant fight infections off.

http/www.fishtanksandponds.info/care-mai...a_poisoning.htm

 

[vthokie]

Well fish can go to all sorts of colours after death so i wouldnt read much into that.
More interested in your stats in ammonia,nitrite,nitrate,and ph.When fish are in bad water quality it takes it's toll on them causing desease, as bad water quality can cause there immune system to shut down causing death as they cant fight infections off.

http/www.fishtanksandponds.info/care-mai...a_poisoning.htm

Thanks for all of your help!