I'd love to use 1/2", but, I got the 1/4" for a real deal, so, as money is always an issue in this hobby, and lack of it is usually the case, you go with what you can
. I'll build it with 1/4", and then reinforce it with supports, (will more than likely go with a sealed top, and use a router to remove sections of it to allow access into the refugium). I'm not too worried about the sump part of it, as there will be plenty of support with the baffles, (but, will still run a 2" - 3" strip all the way around it.... One major flood and I can see me spending a few nights on the couch
).
Thanks again for your help. Hopefully, it will go well, and without too much of a hassle, or leaks, and I'll be one step closer to finally setting up my tank, (this has been a 6 month process so far, so, I don't expect miracles anymore
)
Robert