EDIT: My husband has posted this in the African Cichlid section as well if that's OK, thanks

Hi guys, I've had a disaster in my Malawi tank and I have no idea why. Yesterday evening I fed the fish as normal around 6:00pm and watched them for a while, everything was fine. Then when I next looked in around 8:00 most of the fish were just lying on the sand, with a few gasping at the surface. I tested the water and ammonia and Nitrite came out as 0, nitrate maybe a little high at 50ish. This morning all my Acei are dead, and the rest of the fish look pretty bad

This tank has been set up with no major problems for over a year, I changed the water and rearranged the rocks 2 weeks ago, and a few weeks before that I added 2 more yellow labs, taking the total number of fish to 14. Tank is 75 gallon.

I really have no clue what is wrong, it all just went instantly wrong. It's not as if I even did anything different. Does anyone have any ideas?

This post has been edited by gems: Jun 26 2008, 07:58 AM

I have no knowledge of african cichlids so forgive my ignorance on the species you mention.

Could something have fallen into the water? A liquid of some sort, any polish - you get my drift? What did you feed them? Flake, live food? Frozen?

Where there any signs of illness at all?

If the fish are gasping for air, there is a lack of oxygen, could you increase it, either by airstone or adjust the flow rate of the filter to break the surface of the water more?

Have you checked your pH ??

Haven't checked the pH actually. The filter outlet is pointed upwards and does break the surface.
We feed spirulina pellets, veggie flake with the occasional treats of algae pellets, cucumber & shelled peas.
The only thing I noticed was a few darker patched on one of the yellow labs. But the Acei that died were showing no signs of illness at all

The darker patches on the labs is most likely from feeding the spirulina, it happens sometimes, just cut back on how often you feed it.

I had a similar situation a couple of months after I set up my tank, the best we could figure out was a bacterial infection brought with some catfish I added. Like you the catfish had been in a couple of weeks before it hit. Have a read of my topics and see if it sounds familiar. Another reason to always QT any new fish.

Topic One
Topic Two

dthoffsett, I read the first of your topics and it's almost identical to our situation. Last night we changed the water and added some bacteria meds, but I think it's far too late. As of 8:00am this morning we have only 5 fish left, and they don't look particularly great. Guess quarantine is the only answer, we just have no room left at all in our apartment.
Thanks for the info anyway

I fully understand, go ahead with the medication though, I managed to save a few of my fish thanks to it.

If you have somewhere you could run even a 10gal tank temporarily, you have a QT tank. You can even use a rubbermaid container if you want, it doesn't have to be anything fancy, or even be set up all the time. Just keep extra media in your main tank, and then move it over to the QT when needed, instant cycle.