Random increase in aggression/Feeding?

I have a 120gallon tank with the following:

Blue Sided Fairy Wrasse
2 Purple Firefish
2 Black Clowns
1 Naso Tang (4-5")
1 Tomini Tang (3-4")
1 Blue Jaw Trigger Fish (3.5-4.5")
Coral Beauty
Yellow Watchman Goby
Diamond Goby

Everything has been getting along fine, and everything has been in the tank for over a month, with the exception of the diamond goby, which was added on the 23rd.

Yesterday I did my 3week water change like always and cleaned everything up. Everything was fine until my Halides cut off, and after that, my Tomini tang started chasing my diamond goby all over the tank and my Wrasse, who's been in my tank with the purple firefish for months, randomly started chasing them all over the tank! I have no clue what is going on??

Could I be underfeeding? I feed rotating every other day, twice a day, with New Life Spectrum tropical mix pellets (a couple big pinches of food) and H20 Life Frozen Mysis (one frozen cube morning and night). The Pellets get soaked in H20 Life Vitamins, and the Mysis get drops of Kent Marine Garlic. I also add in Seaweed via Clip every other day as well.

Thoughts?

 

could have just been the stress from the lights. My desjardini seems to go after whoever is closest whenever there is any change. if it's my hand in the tank, he goes after it.

 

idk..it just randomly happened yesterday, hopefully it was just a random thing from the stress of water change to the lights or something

 

anybody else have any thoughts? haha

 

I do not think you are under feeding. May just be an attempt to establish territories and hopefully everyone will figure out the pecking order.

As far as isolated instance, in my experience once it starts it usually continues to some degree. That particular type of tang is reported passive in nature so good luck, but if it continues with more regularity removing him is your best option unfortunately.