My friend helped me transfer the contents of her 40g breeder salt into my new (bought used) 30g breeder today. The tank was set up for almost 10 hours and then there was a mighty cracking sound and the tank started to leak 
. We drained the tank and moved the contents into a 20 long (fish and corals are not happy) only to see that there is a diagonal crack running from the left front corner of the bottom pane all the way to the right front corner. The tank was sitting on a dresser that I leveled prior too. It was leveled carefully and the level was moved to many different points on the dresser to make sure it was level all over. The tank sat perfectly level when initially full with no light showing through the bottom. Now that it is drained and cracked the middle of the bottom pane is bowed upwards but I can't tell if this was caused by the dresser or the crack causing the glass to shift. Why the hell did this tank crack if the dresser it was put on was perfectly level? My friend feels bad for selling me to 30 breeder that broke so she is giving me the 40 breeder the tank was originally in. I am terrified to set it up now in case it too cracks once set up. I am so upset. This was my first saltwater reef tank and I get it set up for barely 12 hours before it cracks!!!!!! PLEASE HELP!!!!
. We drained the tank and moved the contents into a 20 long (fish and corals are not happy) only to see that there is a diagonal crack running from the left front corner of the bottom pane all the way to the right front corner. The tank was sitting on a dresser that I leveled prior too. It was leveled carefully and the level was moved to many different points on the dresser to make sure it was level all over. The tank sat perfectly level when initially full with no light showing through the bottom. Now that it is drained and cracked the middle of the bottom pane is bowed upwards but I can't tell if this was caused by the dresser or the crack causing the glass to shift. Why the hell did this tank crack if the dresser it was put on was perfectly level? My friend feels bad for selling me to 30 breeder that broke so she is giving me the 40 breeder the tank was originally in. I am terrified to set it up now in case it too cracks once set up. I am so upset. This was my first saltwater reef tank and I get it set up for barely 12 hours before it cracks!!!!!! PLEASE HELP!!!!