how many fish you can have is a subjective question.
The most important factor is habitat/aggression.
Do your fish have adequate space to swim, avoid each other, a home etc.
For specific pointers on your set stock list
-4 clowns probably won't work long term better just to go with 2.
-The cardinals will kill each other off down to 2 unless they are all 3 the same gender then they will kill each other off down to one. If you buy them in a store look for two swimming together that's probably a pair that will get along.
Honestly probably just skip them, bangaiis are super boring fish that mostly just float in place.
-Everyone says chalk bass are cool but no experience personally
-Google says that butterfly fish eats corals
2nd most important factor is nutrients. This is reef tank 200 level, but to simplify as much as possible the more fish, the more poop, the more poop the more ammonia, the more ammonia the more nitrogen, the more nitrogen the more food for corals and or algae.
I don't know if your keeping corals so I won't go more in depth.
A general rule of thumb is one snail or crab per 1 - 2 gallons of water. Although you won't need this many immediately.
If your keeping corals you'll want a more robust clean up crew. If your not keeping corals you'll want at least a small amount to eat uneaten food but beyond that its personal prefence. It might look ugly but Algae won't hurt anything in a tank without corals.
MOST IMPORTANTLY
Quarantine all your fish!!!!!!!!
2024 Quarantine Procedures Jay Hemdal David Scarborough Protozoans (Cryptocaryon/ich, Amyloodinium/velvet) and Metazoan trematodes/flukes are by far the most common parasites found on newly acquired fish. A carefully managed, proactive quarantine process can effectively eliminate these...
www.reef2reef.com
