Mysterious deaths in Angel tank

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Lyonhart

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Nov 2, 2016
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I have a 90 high well planted with 4 angels about 1 yr old, 5 neon 3 rams, 3 cory and algae eaters. When I started out I had 5 giant danios to cycle the tank. They did fine until one day one ended up dead with a bruise on its side. Within a week all five had been killed. No issue with the rams or neons. Replace danios with 3 diamond tetra. Within the last week two have been killed (one had an injury to its doral fin was quarrantined and died) One left. Not sure which fish is aggressive. Most likely angels. Do not understand why as danios were in tank for 5 months and diamond tetra for a month without problems Does anyone have an idea what is going on? (Note rams chase each other)
 

fishorama

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What size are your angels, adult? Any signs of breeding interest on their part? They can be quite aggressive if a pair forms, toward both other angels & any other fish. At a year old you likely have a sexually mature pair. Or at least fish that are ready, even if, in the unlikely event, you have all 1 sex.
My angels (over many years & several different fish) always wanted at least 3ft of a 4ft tank. They often ram into other fish but sometimes nip them, their mouth are kinda small...but neons are a natural food for them so don't be surprised if they get snacked on too eventually. Corys don't seem to get the idea of "territories". They just wander around, like many schoolers (like tetras & danios), & can become targets too.

The only way to "fix" this is to either remove the pair, or aggressor anyway, to a 29g+ tank or lfs if you don't want to deal w/fry. I'm down to a surviving stunted female in a 75g...now she's mellow...& old.
 
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Lyonhart

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Nov 2, 2016
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What size are your angels, adult? Any signs of breeding interest on their part? They can be quite aggressive if a pair forms, toward both other angels & any other fish. At a year old you likely have a sexually mature pair. Or at least fish that are ready, even if, in the unlikely event, you have all 1 sex.
My angels (over many years & several different fish) always wanted at least 3ft of a 4ft tank. They often ram into other fish but sometimes nip them, their mouth are kinda small...but neons are a natural food for them so don't be surprised if they get snacked on too eventually. Corys don't seem to get the idea of "territories". They just wander around, like many schoolers (like tetras & danios), & can become targets too.

The only way to "fix" this is to either remove the pair, or aggressor anyway, to a 29g+ tank or lfs if you don't want to deal w/fry. I'm down to a surviving stunted female in a 75g...now she's mellow...& old.
What size are your angels, adult? Any signs of breeding interest on their part? They can be quite aggressive if a pair forms, toward both other angels & any other fish. At a year old you likely have a sexually mature pair. Or at least fish that are ready, even if, in the unlikely event, you have all 1 sex.
My angels (over many years & several different fish) always wanted at least 3ft of a 4ft tank. They often ram into other fish but sometimes nip them, their mouth are kinda small...but neons are a natural food for them so don't be surprised if they get snacked on too eventually. Corys don't seem to get the idea of "territories". They just wander around, like many schoolers (like tetras & danios), & can become targets too.

The only way to "fix" this is to either remove the pair, or aggressor anyway, to a 29g+ tank or lfs if you don't want to deal w/fry. I'm down to a surviving stunted female in a 75g...now she's mellow...& old.
No signs of pairing yet but I am closely watching. Size is about 2/12" for the Koi and black veil, another veil is about 3 1/2" and the other is 3 1/2" with a small body.

You are correct in that the damage seems to be blunt force more than biting. Thank you for your response and sharing your expertise.
 

FreshyFresh

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Sounds like you've had a lot of new additions to this tank. This is almost always going to introduce something into the tank that your other fish have not been exposed to before. If your'e lucky nothing happens, but it's always a roll of the dice.
 

Lyonhart

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Nov 2, 2016
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Sounds like you've had a lot of new additions to this tank. This is almost always going to introduce something into the tank that your other fish have not been exposed to before. If your'e lucky nothing happens, but it's always a roll of the dice.
Thanks, the danios were in the tank for a long time before the Angels and the diamond tetra were fine until a week or so ago. Probably their dithering behavior irritated one of the angels.
 

fishorama

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I haven't kept them but Chinese algae eaters have a very aggressive reputation...that may be the problem, or part of it.

What size were your angels when you got them? They seem a bit smaller than I'd expect after a year but stunting is not uncommon. Are your measurements not including fins? That's how I measure or guesstimate fish especially long finned types.

& to cover all bases, water are you water parameters & maintenance schedules?
 
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