75 Gallon Tank Glofish tetra being aggressive to angelfish

Recently I noticed one glofish tetra in particular occasionally trying to nip my angelfishs fins. I haven’t seen the behavior in the others, can anyone explain why that one has this behavior? I’ve kept angelfish and glofish tetra for 1+ years and although I’ve noticed the nipping towards other long finned fish (that I’ve now separated), I never knew that my angelfish were also bothered by them.

75-Gallon Stock
8-Glofish tetra
2 adult angelfish + 3 smaller angelfish (1-2 inch)
1 kuhli loach (may get more soon)
2 adult bristlenose pleco
1 clown(?) pleco
1 shell dweller (temporarily in the tank due to some hierarchy issues in my other shell dweller tank)

Tank Parameters
Ammonia: 0
Nitrite: 0
Nitrate: 10-20
pH: 8.0
Chlorine:0

 

You may need to up the numbers in the tetra school. They tend to pay attention to each other more when there are more in the school. Idk how many you can get away with and this may still not be the answer but it could help. If anything I'd say add 4 or 5 more tetra and it should help but idk for sure.

 

Skirt Tetras are fin nippers.

I had 1 who I called Jack the Ripper with 2 confirmed kills and 3 suspected kills after a bad water change.

Once my water parameters were good, he stopped attacking.

I think 8 is fine in terms of numbers. I am down to 3 now ( different glowfish than my originals - I originally had 8) and no attacks. They do 'charge' other fish to let them know it's their territory but no damage.

Are you seeing breeding behaviors? I say this based on how my skirt/glow fish will chase one another - definite breeding behavior.


It's all about survival instincts - stressed fish = attacks.

do you have enough decor to break line of sight so fish can retreat?

Running sorority/harem tanks with Bettas for 2 year, IMO line of sight is easiest way to deter an attack. About 1.5 years ago - I introduced bettas into my 38 gallon tetra/cory cat tank.

Now I have 6 bettas in there and minimal issues. Don't get me wrong, I'm checking all the time for any issues. I have 2 backup 10 gallon tanks I can use at any given time. If a betta fails in the community tank, they go into a solo tank. some fish just aren't accepted.

Silver dollar fish which are basically really big tetras ( something I heard in a you tube video and makes perfect sense, as they behave the same) they really require hiding places to feel safe.

If your tank is stable, no water issues, I think Line of sight can help fix it.

 

Skirt Tetras are fin nippers.

I had 1 who I called Jack the Ripper with 2 confirmed kills and 3 suspected kills after a bad water change.

Once my water parameters were good, he stopped attacking.

I think 8 is fine in terms of numbers. I am down to 3 now ( different glowfish than my originals - I originally had 8) and no attacks. They do 'charge' other fish to let them know it's their territory but no damage.

Are you seeing breeding behaviors? I say this based on how my skirt/glow fish will chase one another - definite breeding behavior.


It's all about survival instincts - stressed fish = attacks.

do you have enough decor to break line of sight so fish can retreat?

Running sorority/harem tanks with Bettas for 2 year, IMO line of sight is easiest way to deter an attack. About 1.5 years ago - I introduced bettas into my 38 gallon tetra/cory cat tank.

Now I have 6 bettas in there and minimal issues. Don't get me wrong, I'm checking all the time for any issues. I have 2 backup 10 gallon tanks I can use at any given time. If a betta fails in the community tank, they go into a solo tank. some fish just aren't accepted.

Silver dollar fish which are basically really big tetras ( something I heard in a you tube video and makes perfect sense, as they behave the same) they really require hiding places to feel safe.

If your tank is stable, no water issues, I think Line of sight can help fix it.

Ok that’s good news then because right now my tank doesn’t have a lot of decor because I’m currently rescaping it. Hopefully after I’m done with that the aggression will go down

 

Skirt Tetras are fin nippers.

I had 1 who I called Jack the Ripper with 2 confirmed kills and 3 suspected kills after a bad water change.

Once my water parameters were good, he stopped attacking.

I think 8 is fine in terms of numbers. I am down to 3 now ( different glowfish than my originals - I originally had 8) and no attacks. They do 'charge' other fish to let them know it's their territory but no damage.

Are you seeing breeding behaviors? I say this based on how my skirt/glow fish will chase one another - definite breeding behavior.


It's all about survival instincts - stressed fish = attacks.

do you have enough decor to break line of sight so fish can retreat?

Running sorority/harem tanks with Bettas for 2 year, IMO line of sight is easiest way to deter an attack. About 1.5 years ago - I introduced bettas into my 38 gallon tetra/cory cat tank.

Now I have 6 bettas in there and minimal issues. Don't get me wrong, I'm checking all the time for any issues. I have 2 backup 10 gallon tanks I can use at any given time. If a betta fails in the community tank, they go into a solo tank. some fish just aren't accepted.

Silver dollar fish which are basically really big tetras ( something I heard in a you tube video and makes perfect sense, as they behave the same) they really require hiding places to feel safe.

If your tank is stable, no water issues, I think Line of sight can help fix it.

We put a group of 5 long finned skirt tetras in my daughter's tank. One of them murdered all the others within a few days. It would only happen at night at first, so we weren't sure why the fish were losing their fins (was it fin rot/etc?). Then towards the end we saw it during the day. Relentless little **** that fish was lol. He went back after we figured it out, but unfortunately too late for the others.

Based on that episode I'd be terrified to put one with my angels, but certainly adding a lot of decor/plants should help. I hope it works out!

 

I agree that some tetras can be problematic if there aren't enough of them in the tank, but eight is generally enough.

Like Debbie1986, I suspect a lack of sight breaks to be at least part of the issue. I'd encourage you to add some good sized live plants, or floating plants, as soon as possible.