So this 'fuge has been under my tank for about 7 years now... I moved is about 2.5 years ago and didn't see this crazing, so it's only formed since the move.... I've found some conflicting information about crazing on acrylic tanks, and so much seems related to optical concerns - this is a sump/fuge under the tank, I have no concerns about the optics.... I just don't really wanna come in some day with 15 gallons of salt water on my office floor... Some pics of the situation are below, obviously it's held water to this point, and I've seen some people saying they used crazed tanks for years with no problems, others say to replace immediately... and it can't be fixed. But what if i use weldon to laminate a sheet that overlaps the crazed area by a large margin? Again, not worried about optics. Thanks all, it's been a while since I've been active here, restarting a tank that crashed over a year ago, and wanting to get back into the hobby more - but would like to save some money this so around for new equipment rather than replacing much of what I have.