125 gallon first real build

Hello all,
i started out with a simple 45 gallon tank and after about 5 months realized this was too small for me. so decided to upgrade. so wanted to show some pics of my tank in its somewhat beginners stage and any advice is appreciated.
tank is 48 x 24 x 24 inches, i have a 30 gallon im using as the sump / refugium with a 300 gallon protein skimmer. using live rock and macro algae with lighting for filtering. theres about 150 pounds of like rock with 140 pounds of sand and crushed coral.

have 4 clowns 2 Picasso clowns, one ocellaris, and a large sebae.
3 damsels, two domino and one yellow tail,
a yellow capped goby, and a lawnmower blenny and a dragonet
3 tangs, a powder blue, purple, and yellow tang

 

Looks good. How do the tangs get along? I haven't bothered research them much since I have a 29 but I was under the impression 3 would fight a lot even in a tank that size.

EDIT: I just realized if I had a tank big enough, you have the 3 exact tangs I would get. Good choice.

 

the tangs get along surprisingly well the powder blue and the purple have become mates they swim together and hang out with no aggression, the yellow tang showed aggression when first adding the purple but has since accepted the new tang. The weird relationship i dont understand is between my clowns i had the sebae, an ocellaris, and a picasso. the picasso and ocellaris have paired up and swim and do everything together but when I added the new tang picasso to the tank a smaller one than the existing one, the original picasso(larger one) shows lots of aggression to the new little one. I know clowns can be stubborn of other species of clown but thought they were accepting of the same species.