empty the tank putting your water into a new rinsed out plastic garbage can from home depot a 30 gal can cost about $10.00 - $15.00. They are just giant buckets but more stable. They are dark and they hold the heat better than a reg. bucket.
Dry off the tank and go over every seem with silicon, you can buy it at the fish store. Wait 24 hrs and add your water back. If it has stopped leaking and it should, you can add your serviving critters.
You can put your sand and rocks even the fish into the garbage can with a heater and air stone, Put your coral in a seperate can if possible. coral kept in the dark as long as it is kept warm should be alright for 48 hrs.
If you don't have an air stone use your powerheads to stir the water and distribute the heat from the heater.
