# Species kill off... what the heck??



## Lexus (Jan 19, 2005)

Last week I awoke to 11 out of my 19 N. Pulcher cichlids dead. They are in the tank listed below... 55G. All the other fish in the tank were acting fine but there lay 11 fish. The remaining 8 seemed alright, some looked like they were on death's door, others not. The tank was ready for a water change and I immediately proceeded to do that after the deaths. I didn’t catch the parameters because I was so dumbfounded by the loss. They were all siblings out of 1 or 2 fry batches. What I don’t get is the other fish tend to be more sensitive then them so why only one species of fish?? Weird. I did add more big rocks but over a month ago so I don’t think it could be that. I also wondered about ammonia and nitrate/ites being out of whack but wouldn’t everyone have died or acted weird? I also think it’s strange that I bought these fish in January as very small fry and they are not full grown yet after 6 months. Any thoughts?


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## Guest (Jul 1, 2008)

If that many died and others were acting as though they were on the way, I'd blame it on water quality. If ammonia and nitrites were high, all the fish aren't necessarily going to kick the bucket at the same time, seeing as how ammonia poisoning affects different fish at different rates. The way you described it sounds like a water quality issue to me though. You said you did a water change, so how do they seem now?


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## emc7 (Jul 23, 2005)

I'm with Scuba here. When a lot of fish drop dead at once and the dying stops after you change water, it was probably a water quality issue. You might have neglected the tank too long (its easy to overfeed when you have growing fry). Or you could have had really bad luck. Say a fish or two is killed by other fish the same time your power goes out and you have no filter for several hours. It doesn't take long for the first dead fish to create a lot of ammonia in a short time. 

You should also check for equipment malfunctions. A heater that sticks on for a while before cutting out will hurt some fish more than others, as will a heater that doesn't heat. Filters that have damaged cords or rocks in the impeller chamber could intermittently go out also. Its always good to have more than one filter. A co2 system could malfunction and overdose the fish. 

Or you could mess up chemicals during a water change, too much or too little buffer, or not enough dechlor. Or your water system could mess up and put in too much chloramine. All of these are water quality issues. 

As for the fish not growing fast there are two possibilities that aren't mutual exclusive. 1. Poor nutrition, something lacking in the diet. or 2. Tank too small/not enough water changes. Fish do release molecules into the water that inhibit the growth of fish. If you put the same number of fry in two tanks with equivalent water changes, the fry in the larger tank will grow faster. Its also been shown that up to a point the more water you change in tank the faster the fry will grow. Its possible to raise a large number of fry in a very small tank and still have them grow, if the tank has a large water change several times a day.


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## Lexus (Jan 19, 2005)

Ya I figured it prob was the tank quality. 

The fish now are fine and recovered quite quickly so that is another indicator it was water quality. Just shocking that 11 in one night and they all looked to die at the same time looking at the decomposition.

I have Panda cories and Angels in there which always seem to be the first to act sick so it was unusual to see the fry go ill. 

The fry were raised in a 29G all by themselves for the first couple of months and then moved to the 55. The fish are not large and do not grow large so I can't imagine there being too many. Especially for a cichlid tank. The tank is fed bloodworms, shrimp, color flakes, shrimp pellets and algae wafers and the cichlids sample all of it. 

I am on well water so no declor, not product usually used except the last few times I have used Aquaclear declor stuff in it... but the water had not been changed in awhile so it couldnt be that. 

I checked all the equipment when it happened... everything functioning fine.


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