[longbowaj]

Yes this can and has been done. I did a 20gal high a while ago. I suggest lots of fresh razor blades to get all the silicon scum off. The top edge of the glass may be somewhat jagged so I suggest using a whetstone to smooth it out.

 

[longbowaj]

I have never heard of anyone having problems when doing this to a 20gal tank. I agree that you can have support issues once you go much bigger though.

 

[longbowaj]

Again I don't think a 20gal high tank will bow, mine doesn't. This is all dependent on the thickness of the glass. If you get a name brand tank I don't think you will have problems. I have both the top and bottom rims off. Mine has only been running for ~6 months but when I was reading up on this I found several people that have had theirs going for several years with no problems.

 

[longbowaj]

Don't mind the bad photography and the scape is still being worked on.

Before (basically before i found APC)

After (in all the clear shots you can see my reflection)