Exclusively pumping

I plan on exclusively pumping for personal reasons. I mentioned to my husband that I read you’re supposed to pump every two hours even at night to produce enough milk, and he said that was ridiculous and I need to stop getting my information off the internet. Apparently his sons mother pumped and she didn’t have to do it nearly as much. Never mind that was ten years ago, and they broke up right after the kid was born, he’s still an expert on everything. It’s kind of driving me crazy.

Realistically how often do you pump if you’re exclusively pumping, and how do you get your husband to quit acting like a know it all?