Black and white fish is Bandit Angelfish, endemic to Hawaii. I have had him 5 weeks. He is just under 3 inches. I think they get up to 8 or 9 inches. They have a reputation of being difficult to begin feeding in aquarium. I got him from. POTO, conditioned to eat , and he is a pig. I was very very nervous about adding a small expensive fish to an extablished tank with 2 other angelfish. Flame and Black Velvet. But it is working. The photo bombing fish is the biggest fish in tank, Pink Tail Triggerfish, 6 inches plus.( I will try to post a better pic of him.)
I haven't lost any fish to this one.( fingers crossed). Years ago in a different tank , as I was feeding , a long nose hawk fish got excited and bounced/ flitted into a carpet. It was shocking and fast ! Completely closed up on him before I could close my mouth. Long nose Hawks always struck me as dumb.
And in the same tank a few weeks later I was all excited releasing a Black Cap Basselet into tank. As soon as the Black Cap hit the water , I 'm talking 2 seconds max, a 10 inch snowflake moray eel shoots out of his cave and engulfs him. $ 60 dollar meal -OUCH.
I really do not know . It is a factor of lights , and chemistry( Ca / Alkalinity) . This tank has been set up about 4 years. Lights are four VHO and 4 400 watt metal halides. ( So lights are older than 4 years) . VHO are becoming hard to buy now, so I may go to LED by force. I have a tank , same size, at office that already is on LED. I think that tank has purple algae too. I will try to find pictures, or take new ones of it tomorrow. I spent so much initially on these lights at home, that I hate to abandon just to chase new thing. Although electricity and bulb replacement on this set up is probably crazy. If you get conditions right , you get purple algae, if not , you get hair algae.
By the way, the first time we plugged those 4 400 watt halide bulbs in , it tripped all breakers for half of house. Now I have 2 dedicated circuits for aquarium only. One for 4 400 watt halides, and one for everything else- VHO s, wave maker,pumps , calcium reactor, chiller, skimmer, etc.
The office tank never had the overkill lights , and actually the invertebrates look better in some ways there. Lots of pulsing Xenia, leather coral, zoanthids, torch, stuff like that.