Seagate Error codes

@RVTJR - Yeah - Watching videos is getting pretty difficult. The video freezes every 3-5 minutes for ~5 seconds. Actually I guess I didn't explain my setup status very well. After the first disk died (slot#3), it was replaced within a few days. I just haven't gotten around to RMA'ing it yet because I didn't think it was in warranty. So I was back up to 4 good drives again. Then I started getting the reallocation errors a few weeks ago (slot#4), and was advised by StephenB in a different thread that any errors over 50 was bad. I was at 20432, so I replaced it. The new drives just came in two days ago. I replaced slot#4 with a new ST4000DM000 (wanted to expand storage as well) and after it finished it's sync, I also replaced slot#1 with another ST4000DM000, since this had the longest power on hours, power cycle count, etc. So currently I have about 8 hours left before the sync for the last drive to sync. Will the extra storage space show up right away? Or after the sync, will it then need to do and expansion operation as well?

BTW...All data is also backed up to (2) external drives (some to one, the rest to another, since I don't have anything big enough on it's own). The drives I get as replacements (along with the still good drive from slot#1) will be used with a new Shuttle OmniNAS KD20 I just got to help up with my backups of my backups. Reviews of the KD20 were pretty bad, but for $48 bucks, it should be okay for backups. We'll see!

Also, the second drive never finished the SeaTools for DOS analysis. Something bombed out at 70%. Ran a quick check with SeaTools for Windows, and it passed the SMART test, but gave error code F49899E5 doing the Short DST. So any ideas what F49899E5 or E161CB4A mean?