Slow, slow, slow
I wouldn't start as high as that, I'd go for maybe 10 bubbles per miinute, maybe 20 at the most. The system may be unstable at the start, sometimes things are temperature dependant and the bubble rate that you thought you began at is not what you may find several hours later.
Be sure to begin in the morning when you can be around all day to watch for instabilities in the bubble rate or the fish for signs of distress.
Personallly, I started at 6 bubbles per minute, which is about the slowest flow I could get through the needle valve. After a few days I increased that, after I had seen the pH that resulted in -- since the tank was full of new water it actually took a little bit longer to see what the tap water would settle out to as entrained CO2 left but was supplimented with injected CO2.
Then I still watched very carefully, for AM and PM pH levels, to see if I was near a danger zone or maybe needed to turn the CO2 off at night. In my case the pH changed too rapidly as the CO2 was turned off for the night so I leave it on.
How many bubbles per minute is too much is a very individual thing. In my 59 gallons, with a glass top, the best bubble rate depends on how much surface agitation the filter returns create. The gooseneck return is much different than the submerged spraybar. My water is moderately hard and well buffered and it bounces back easily. Yours will be different, test and be certain.
