if you go slow you can cut it no problem, the finish wont be very nice so it will need some other work as well afterwards, i havent cut one 72" but i cut a 1" strip off a piece that was 24" x24" through my wet saw, just your average diamond blade, where the glass is so thick it actually cuts very easily. theres a video on my tank journal of us cutting it check it out its just a crap mastercraft saw and took only 3 mins to cut one inch off of two pieces. both pieces turned out really well. cheers:)

Cutting the tank apart, cleaning the glass and then taking in in to get cut is a PITA. Probably cheaper in time and money for a new one. you could consider adding another piece of glass 6" up That too would be a pita but you could play around with having a 6" tank under ie. reaction chamber etc. Just throwing ideas out there nothing really practical. (disclaimer having fun with this not a viable solution).

Kevin

leave it 30 and add a brace a across the top front and the coast to coast to brace the back?

What about a glass cutter? you know, the little hand held tool you score the glass with and then snap it? I know it takes some practice, and maybe that's way to long of a piece of glass (or thick) to work, but I think if it were possible, then you should have a nice straight line and you could touch up the sharp edge with a dremel. I havn't tried cutting cutting anything thicker than 1/4" this way though...

I dunno... seems safer then running a skill saw through it. :)

Its not the top that bows its the whole front panel the euro bracing keeps the top straight.

I think I am going to try and cut it while still together on saturday I will take lots of photos to let you guy know how it goes. I am going to tape the entire cut so that I dont get as much chipping hopefully glass is like wood and that will help. lol I am also going to make a 2 x 2 frame inside the tank to support where I am cutting.

Why not sell it and buy a 24" tall tank

I wouldnt feel right selling a tank that I dont think is safe to hold water.

Wear safety glasses!

BTW all 230 gallon standard tanks bow out from the center like you described, basically poor design as the glass should be thicker and braced better. If it has 1/2" glass and a huge center brace in the center it's the standard 230. It will still hold water fine, it'll take more than a little bow to separate those seams.

Well I managed to cut the tank down to 24 inches without breaking it. There is a couple of chips but not that bad. I found that masking tape did not help to reduce chipping and that starfire glass chips more then regular glass. I will post pictures later today.