Running out of room on External and Internal HDDs

Hi Everyone!

I started to post here about comparing two external HDD's for storage so I find out where I duplicated some iPhoto or other file. See my posting in this link: How to print a list of file contents of a HDD https://discussions.apple.com/thread/6866622

The problem extends to the fact that the Main HD of the Mac G4, running Tiger 10.4.11, is getting full and I'm getting "Startup Disk is Almost Full" readings very often.

All I have to do is open a few tabs on just one window surfing the modern internet and its too much for the old computer. I'm using TenFourFox7450 and OmniWeb to do the surfing depending upon which Email I need to access (both are old and sites say there is lack of functionality in composing and reading Emails as a result of this).

I get the same warning after using the "Mac" mail icon itself, as I have more than one Email attached to that and they keep getting new emails I need to check.

After running that for a while I get this response, even after closing Mail, its too little free space on the HDD for the "journaling" process I know something about, that has to occur to keep the applications running smoothly. I have about 3.50 GB left on the 60GB internal HD and running out of space on the external HDD's to put stuff. (I have another question about that problem I'll post under this link___________(I can't edit after 15 minutes so will reply to myself when I create the link!)

As the image shows, the only choice is to either stop "Finder" i.e. everything goes if you do that. Or I have to shut down the computer and start it up again, and the 3.50 GB free space appears again.

I guess I should say that the warning comes when the free space drops down to 900 or less MB.... I don't SAVE anything new... its just running the applications somehow eats up the available free HD space, until I get the warning window.

I know, its an old computer...... but trying to figure my way out of this to keep using it.

Thank you for reading this !

Mac_Help