Would a 75 gallon-80 gallon work because volitans lionfish grow 15" and niger triggers grow 16"
I should think that will be fine - I would say minumum of 55 gallons but obviously the bigger the better!
Read this about care of lionfish
Best of luck!
I wouldn't keep a trigger with a lionfish. They can both be aggressive but the triggers more so...
Well the other day I was at a pet store and I saw a red volitan lionfish in the same tank with a picasso trigger. I'd think it would be a bad idea to put a lionfish with a very aggressive trigger such as an undulate trigger.