Rapid tail rot(?) on captive-bred Ocellaris

[KGNZ]

This juvenile Ocellaris is captive-bred and about 4-5 months old and was added to a new tank after a completed tank cycle one month ago.

Current water parameters:
Water parameters appear fine: Ammonia 0ppm, Nitrite 0ppm, Nitrate 20ppm, pH 8.4, Water temp 26°C, Salinity 1.024.

Over the past 48 hours I've noticed this fish's tail rapidly deteriorating and becoming pale

The fish has been eating fine, a mix of flakes and mysis - though in the past 24 hours the tail has been slowing the fish down a lot and seems to be eating less and resting on the sand more.

Additional history:
Some blemishes/lesions appeared on only the white parts of the fish over the first 10 days in the tank. The white tail strip also darkened over that period. I tried Melafix without much improvement, but the lesions seem to have stabilized without progressing. I made a post here: https://www.reef2reef.com/threads/clownfish-bruising-lesion.936964/post-12892727

I've not seen aggression other than this fish darting/charging towards the other clown in the pair on the first couple days in the tank. Not seen any aggression since, in fact I see them resting on the sand together quite often.

I have Metroplex, Kanaplex and Focus on hand. If I were to administer any of these, is it alright to dose the main tank (fish only - and only the pair of Ocellaris). Or do I need to separate the fish into QT?

Greatly appreciate any advice!

Attached: Video is from today. Photo is from yesterday evening.

 

[vetteguy53081]

This juvenile Ocellaris is captive-bred and about 4-5 months old and was added to a new tank after a completed tank cycle one month ago.

Current water parameters:
Water parameters appear fine: Ammonia 0ppm, Nitrite 0ppm, Nitrate 20ppm, pH 8.4, Water temp 26°C, Salinity 1.024.

Over the past 48 hours I've noticed this fish's tail rapidly deteriorating and becoming pale

The fish has been eating fine, a mix of flakes and mysis - though in the past 24 hours the tail has been slowing the fish down a lot and seems to be eating less and resting on the sand more.

Additional history:
Some blemishes/lesions appeared on only the white parts of the fish over the first 10 days in the tank. The white tail strip also darkened over that period. I tried Melafix without much improvement, but the lesions seem to have stabilized without progressing. I made a post here: https://www.reef2reef.com/threads/clownfish-bruising-lesion.936964/post-12892727

I've not seen aggression other than this fish darting/charging towards the other clown in the pair on the first couple days in the tank. Not seen any aggression since, in fact I see them resting on the sand together quite often.

I have Metroplex, Kanaplex and Focus on hand. If I were to administer any of these, is it alright to dose the main tank (fish only - and only the pair of Ocellaris). Or do I need to separate the fish into QT?

Greatly appreciate any advice!

Attached: Video is from today. Photo is from yesterday evening.

This looks like aggression damage and likely from other clown which is likely a female
What other occupants in the tank?
This will repair on its own as long as it’s not continued to be nipped at
May require isolating the other clown