Cleaning an old tank


Reefing newb
Hello, I haven't been here for a while. I was all ready to set up my tank but life got in the way. Attempt 2 is getting started but my 55 gallon tank needs to be cleaned. I read online that a good way to clean the tank was to use vinegar solution. I went to my local aquarium and they said I should only clean with a bleach solution. The vinegar will stay in the tank and kill the fish. The tank used to be used for freshwater fish and there is some stubborn algae in it but the tank itself has been empty for about 2 years.

My 110 sat for a week filled with a vinegar solution, then was thoroughly rinsed out. I've had it up for a year and fish are good! I would be more afraid of bleach than vinegar. I can drink vinegar and not die.