Sorry for taking so long with an update - I have finally got my 125 in good enough shape to post. Right now I have the tank full of water and the filter up and running. Since I lost some of my budget due to the car accident, I have fallen back to using some of my equipment from my reef-keeping days.
I have been fighting with a few leaks, but nothing serious. Assuming everything seems fine with this system, I will begin working with the glass to build my 60 gallon tanks.
Well, I attempted to assemble one of my 60G tanks yesterday - it didn't turn out well, but I did learn a bit while assembling.
I ended up with half of the seams looking great, and the other half with lots of bubbles (which will need to be re-done). Unfortunately, the seams that are bad are on opposite corners of the tank. This means I'll need to completely disassemble the tank and try again.
The thing I am glad I learned this time was that if you are just learning to build a tank from glass panes, be sure to use CLEAR silicone. If I had used black or white, I'd have no idea that I had the seam issues. If I had just used it as-is, i t would be quite likely that the tank would have failed between weeks and months later.
The image on the left is a good seam (ignore the spillover at the top and bottom).
The image on the right has a hazy seam and that gap in the middle is where there is no silicone! (by far the worst seam)
I'll tear this tank up and try again when I get a chance. All in all, a great learning experience, but not terribly productive.