Do my corals need fish to thrive and transfer question?

[Steve1500]

I am transferring from a 75G to a brand new 180G tank but I don't want to transfer my corals to the 180 until it is mature enough to accept them (3-4 months from now). The 180 went through the nitro cycle about 1 month ago.

If I transfer all of my fish (9) from the 75 to the 180, will it cause issues with bioload etc in the 75G tank? I plan on transferring over a 2-3 week period so I don't shock the 75G corals. Or should I leave some fish in there until I transfer the corals to the 180?

Also, I have read that it is best to slowly add new fish to a new tank but in this case, I also want to keep aggression down by adding most fish at the same time. So, I plan to add two of my existing tangs (yellow and blue hippo) and other fish from my 75 to the 180. At the same time, I have 2 additional tangs (purple and kole) in a QT and would like to add them to the 180 about the same time as the yellow and blue hippo.

Which is better: Add tangs about the same time to ease aggression or add them a week or two apart to ease in a bioload spike? Will this even matter with a 180G tank? Prior to adding the tangs (one week), I will transfer 2 clowns, 1 basselet, cardinal, damsel and coral beauty angel from the 75 to the 180.

Clear as mud?

 

[EmdeReef]

I would add all the tangs at the same time, ideally after other fish. Once your 180 is properly cycled, stress test it with some extra ammonia in the evening and see if it’s at zero in the morning. Unless you are adding 20 fish at the same time your bioload should handle it especially in a 180g tank. You can get some bacteria to add after adding fish.

Your corals should be fine without fish as long as you maintain proper parameters and keep nutrients above zero.