My favorite fish is dead. Any theories?

**kjr928** · 10-23-2012, 10:01 AM

I have a 90g that I just revamped.
It had: 1 angel, 5-6 loaches, 6 bloodfins, 3 female bettas, 1 rainbow shark

Last week I added 6 more bloodfins and this past weekend I added 6 quarter sized angels (all healthy from what I can see). Last night I hooked up my CO2 to my powerhead and I had it going about 1 bubble every 4 seconds. I also added a piece of driftwood a few days ago. Those are the only recent changes.

This morning I woke up and the angel I've had for at least 5 years was dead in the tank.

So I quickly did a water test and the results were:
Ammonia 0
Nitrite 0
Nitrate 10
ph 6.6

The fish didn't look sick - no spots, no fuzz, no funny behavior, etc. Any theories? I'm worried about my other fish.

RIP Angel!

**TL1000RSquid** · 10-23-2012, 10:26 AM

If everyone else seems to be acting and looking ok, could just be one of those things that happen, I occasionally have an unexplained death, just keep a close eye on everyone for the next few days.

Was the angel a juvie or adult when you originally purchased?

The new fish were they in QT or just purchased this weekend?

**kjr928** · 10-23-2012, 10:37 AM

I think the angel was a big juvie when I got it, like a half dollar size. It's so long ago though that I can't remember.

I did not quarantine the new fish, just acclimated them and put them in. One of the bloodfins didn't look too great and he died the same day, but other than that everyone else looks good. The bloodfins went in last Wednesday and the new angels went in on Sunday. I picked the angels up from a private breeder and they are definitely very healthy. Bloodfins came from a fish store.

**TL1000RSquid** · 10-23-2012, 12:05 PM

Not old age then. Like I said it just happens sometimes lost a betta I had for a year and a half a few weeks back no signs of problems just dead when I woke up, noone else in the same tank died or looked ill.

**Dangerdoll** · 10-23-2012, 12:24 PM

when you revamped the tank, did you stir up the substrate or add new?

**kjr928** · 10-23-2012, 1:30 PM

The original 90g that they were in had a snapped center support. So I actually got a new tank and transferred everything. Same substrate, but I'm sure it got stirred up plenty during the transfer.

The water has tannins in it now from the wood that's in there, but I don't think that would have done it. And I've got CO2 running at one bubble every 4 minutes (just starting to learn about CO2 for planted tanks) - but I don't think that would have done it either.

So far everybody else looks good. I'm making sure to check back often. I'm not sure if I should be worried about the others or not.

**rufioman** · 10-23-2012, 2:04 PM

My money's on the c02, but that's just because I've always been a bit afraid of the stuff with regard to putting it in my aquariums. I too just had a 5+ year old angel die on me, and that was rough :/

**TL1000RSquid** · 10-23-2012, 2:47 PM

I would think if it were the c02 it would of affected more then one fish? I'm no expert on it though my planted tanks are low tech mostly cause I too worry I'd kill everything with a DIY c02 and dont want to spend the money on a high end one.

**kjr928** · 10-23-2012, 3:13 PM

I have a CO2 tank with a regulator, so I'm sure it was only letting out 1 bubble every 4 seconds. I turned the CO2 on for the first time last night. Is it possible the fish got poisoned by CO2?

**rufioman** · 10-23-2012, 6:11 PM

It's a 5 year old angelfish though. They're not as hardy at that age, and that is coming from firsthand experience. It would've made more sense if all of the fish had died, thus I will say that I retract my statement. However I am intrigued by the new tank. That might've been stressful enough on him....maybe. Rapid changes in chemistry, etc.