Storage workflow for TikTok and CapCut on iPhone 12

Hello,

My girlfriend is starting to make daily tiktoks and she's running into storage issues.

She has an iPhone 12 with 128gb of storage (2TB iCloud storage). Recently, I turned off photo sync with iCloud, deleted all the photos on her phone, and re-synced. This brought Photos storage down to approximately 2gb. Within a couple days her photos app has increased to 50gb and CapCut is around 30gb.

I'm trying to help her figure out a workflow to film videos and edit in CapCut (on her phone) without consuming storage.

My understanding of iCloud is that its purpose is more tailored to syncing across devices, rather than backup. Side note: I used to have a Pixel, and Google Photos had a button "Free Up Storage", that would delete the photo from the device once it had been uploaded to the cloud. I wish iCloud had this feature!

I have a 1TB Sandisk SSD that isn't currently being used, but I'm not sure the most effective way to use it for her workflow.

I tried plugging this SSD directly into my phone (USB-C), but the SSD needs power to run, so it will not connect directly to a phone.

Does anyone have a solution to this problem?

Thanks!