Ionic / Firebase realtime database HELP

Hello,

I currently use ionic with a firebase realtime database, however I have a problem. I have a comment page and the problem following this pose:
When I’m on the comments page if a lot of people post a comment it’s constantly updating, that’s why I would like the data to appear at the opening and after it is no longer in direct, that I recharge them with an ion-refresh (I have already set up, it’s just the part of deactivate the direct firebase comments I do not come) …

Thank you for helping me…

Doesn’t that beat the entire purpose of a realtime database? What about unsubscribing after the snapshot has loaded and after that you can do whatever you want to do (like subscribing again or something like that)