Angelfish nipping

[Simon_DG]

Hello,
So i have 2 angelfish 1 is defenitly a female and the other one im not sure.. i got these 2 from seperate LFS but they where getting along for months without any aggresion always swimming together. I restarted the planted tank 1 week ago and now 1 of them keeps nipping the other one dorsal fin.. its allready damaged a little bit and so is his dorsal fin to but i dident see the other one nip at him but why are they doing it and should i be worried they would get along perfect for months and now after the restart and replant they nip eachother dorsel fin to the point of damage.. i allready applied some skin infection medicine to his fin so its doesent get a infection i do this 1 every 1/2 days..

[Autumnsky]

Check for the water parameters to be in the safe zone. Water in unsafe zones can increase aggressive behavior.

What size is your tank?

What other fish are in the tank?

Is the tank cycled with an actively producing beneficial bacteria population? Have you replaced the media pads / rinsed them in plain tap water, not dechlorinated?

Changed or washed the substrate, you mentioned "restarted" the planted tank???

Edited: adding that as the fish mature they get the hormonal surges for mating and that can affect their behavior to each other and the other fish which they perceive as being in "their" territory.

[Simon_DG]

Not a real restart just new plants and externel filter. Its a 66 gallon comunity tank. The angels where allready in the tank when i replanted it. Yes i added filter media from the old filter in the new one. I always wash it with tank water not tap water. I also added a active bacteria dosis for the tank. They stopped niping at each other dorsel fin now i think they where juSt deciding again who is the alpha and who is the betta for the new planting wich made the tank look verry diferent. So looked like new “teritory” but they are healed up now nothing wrong anymore. Thanx for answering me

[BBradbury]

Hello Sim...

Tank problems are generally water problems. First, don't put any chemicals other than the standard water treatment into the tank water. You don't know how your fish will react. Begin a more aggressive water change routine. Slowly, work up to the point you change half the water weekly. Add a little standard aquarium salt to the water. A teaspoon in every five gallons of new, treated tap water. Plant the surface of the tank well. I would include Anacharis, Hornwort and some Dwarf water lettuce. These steps should get the tank and the fish back on track.

B

[Autumnsky]

Oh, good, glad they are doing better now.

The cleanest water always helps in healing, in case anything further in the future.

It does make sense they were having to re-adjust to the newer scape.

[Simon_DG]

No need to do more aggresive water changes now i think the filter is way bigger then the one before. I added the old filtermedium in there plus alot new bioactive media to i alse added a active bacteria dosis for extra bacteria to start with i do a 50% water change every sunday and the water stays good on the parameters i just have some particles floating in the water still and a little bit algea on some plants but i added a new light for the plants so maybe thats that