Do fish need a reason to die?

[mr_algae]

My 80G tank has over 150LBS of cured live rock along with live sand. I had 6 damsels in it for 3 weeks. I did notice a small spike of ammonia followed by a drop off back to 0. Nitrites and Nitrates are 0 as well now. Salinity is right on the money. Saturday morning I went to the LFS and had them check my water as well. they said everything looked good and I was ready to trade the damsels in on other fish. After spending an hour and a half catching the little

[hr]
, I went back to the LFS and got 2 clowns, a coral beauty, and a sailfin tang. All were doing great till this morning when the sailfin tang was up at the water intake for the filter. ALl the others are still happy.The sailfin just came into the LFS that day. Could it just be shock or something? I guess my question is - does there have to be something wrong with my tank? or do some fish just kick the bucket for no reason?

 

[ophiura]

These fish (tang, angel) really need to be in very mature tanks (at least 6 months though for many it may take years or never to keep one for whatever reason)....there are all sorts of variables that we can't test for that can cause harm.
But my greater concern is your ammonia level...do you not have any now? You may have over stocked and overwhelmed your biofilter...sounds like the tank wasn't cycled "hard" and it may be doing that now though you have lots of rock. Anyway, I would watch closely and I would be ready to get those fish (at least the tang and angel) out ASAP. FWIW, IMO you are adding lots of bigger fish too quickly. I prefer to never add more than 1 larger (tang, angel) or two smaller (clowns) at one time.
How did you acclimate your fish?
FWIW, when I worked at an LFS, you could not buy a fish the day it came in. There is a lot of stress there - I would not buy a new fish in most cases. I would wait until at least 2-3 days have past (this is the peak of mortality on new arrivals) and then be sure the animal is behaving well and eating prepared foods.

 

[lefty]

First off...you caught six damsels with 150lbs of live rock in your tank in only an hour and a half?? Wow!
Did you acclimate the fish at all? They should be drip acclimated for at least 1-2 hours; many people like to do it for several more than that (see the side bar titled "Acclimation" for a rundown of this procedure). You also added too many fish at once.
-lefty

 

[mbrands]

Originally posted by ophiura
I would not buy a new fish in most cases. I would wait until at least 2-3 days have past (this is the peak of mortality on new arrivals) and then be sure the animal is behaving well and eating prepared foods.
This is a great idea, especially for wild caught fish. In addition to lowered stress levels, the LFS will get them used to eating flake or other foods so that you won't have issues with trying to feed a new/traumatized fish.

 

[mr_algae]

Originally posted by lefty
First off...you caught six damsels with 150lbs of live rock in your tank in only an hour and a half?? Wow!
Did you acclimate the fish at all?
-lefty
I had to take all my rock out to catch the little bastages.
acclimated for 1 hour.

 

[mr_algae]

All the fish I got were small. I think the load is less now then with the damsels I had.

 

[mr_algae]

Originally posted by ophiura
But my greater concern is your ammonia level...do you not have any now? You may have over stocked and overwhelmed your biofilter...sounds like the tank wasn't cycled "hard" and it may be doing that now though you have lots of rock.
I dont think it will cycle hard with all that LR ans LS I put in there. I have been testing my water daily. about a week or so after i started the tank I had algea growth so I purchased 2 huge snails and they crapped everywhere eating all that algae. I thought for sure my ammonia would go high after that but it never did. I got some crabs and they started taking care of the snail poop. Now all that mess is gone and still good water readings.

 

[ophiura]

Yeah, if you do have that much and they are smaller fish...that would be true. The risk tends to be with slightly larger fish, and the novelty that these are the fish you've been waiting for, which may lead to over feeding and then to an ammonia spike
I just like to really push a tank that shows a potentially weak cycle before putting more fish in - If you put just a bunch of dead shrimp in there and still no ammonia spike, then things are good. But without a hard push, I am always worried about adding a fair number of larger fish at once.
Be forewarned though - you don't really have a large tank so you don't have too many more "spaces" IMO for more fish. This is another reason, again, IMO, to take it slow in stocking. You don't want to see something you like and have to take all that rock out again to make some space for it.
But I would still argue that a newly cycled tank is very young for more delicate fish like angels and tangs, regardless of amount of LR. Those are fish I wouldn't put in until much later.

 

[snipe]

There are many reasons a fish will die. But I do agree with ophiura you should of waiting on the tang and angle. They need to go in the tank last anyways. You should've waited on the fish to and put 1 or 2 in every couple weeks.