iMac OS - clearing and freeing up space

Get Correct Storage Information

Do not use the information from the Storage section of the About This Mac dialog. Ignore the Storage information as it is typically wrong. To find out the correct information for any disk: Select a Desktop disk icon. Press Command-I to open the Get Info window and look at the topmost panel displayed. You will find the disk information displayed for Capacity, Available, and Used. If you have more than one disk/partition then repeat for each one on your Desktop.

The categories found in the Storage section of About This Mac is simply an arbitrary way of displaying files on your drive. There are no such categories actually on the drive.

How to Free Up Space on The Hard Drive

1. You can remove data from your Home folder except for the /Home/Library/ folder.
2. Visit The XLab FAQs and read the FAQ on freeing up space on your hard drive.
3. Also, see Freeing space on your Mac OS X startup disk.
4. What is 'Other' and 'Purgeable' in About This Mac?
5. Files That Make Up the 'Other' Storage Category, and How to Remove Them
6. Free up storage space on your Mac.
7. See Where did my Disk Space go?.
8. Be sure to Empty the Trash to recover the space.
9. Replace the drive with a larger one. Check out OWC for drives, tutorials, and toolkits.
10. Use OmniDiskSweeper or GrandPerspective to search your drive for large files and where they are located.

Do you by chance have a Fusion Drive setup with a 3TB HDD and a 128GB SSD? It's the SSD that only has 25GBs of free space, whereas, the HDD has plenty of free space. In a Fusion Drive configuration, the SSD is not used as a main storage device. It is used to improve the speed of the startup and provide a large cache for the HDD that holds frequently accessed files by transferring them from the HDD to the SSD, transparently.

Does this describe what you have?

Be careful not to confuse storage space with memory (RAM) space. You have 3TBs of storage and 32GBs of RAM or memory.

If you have iCloud turned on (and you should) deleting the photos from any device will delete them on the other devices.

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piploops.com’s server IP address could not be found.

Notice that he has 2.5GBs of unused storage space on the HDD. He doesn't need to delete anything. If he put them on the SSD, then he should transfer them to his HDD. I think he has a Fusion Drive setup.