Hello i have had a 65 gallon reef tank running for about 3 months now. I run a wet/dry system as well as a 75g protein skimmer and maintain good water quality as well as perform weekly water changes. Is there any general rule of thumb for the size or amount of fish i could comfortably keep in a reef aquarium?

it depends on the size of the fish but ide say u could have around 9 or 10 especially if u keep your water quality up