A leaking aquarium can either be replaced or repaired. If the leak is small, repairing it with aquarium sealant is not difficult, says Saltwater Aquarium Essentials. You need aquarium sealant and some acetone to complete the job, and the entire project should take less than 2 hours of work, plus a day for the sealant to completely cure.Continue Reading
Observe the pattern of leaking water carefully to identify the site of the leak. The water may appear to be leaking from the bottom, but often it is leaking from higher up along one of the side seams. When the leak site has been identified, mark it with a pen.
Empty and dry out the aquarium. If the leak is located fairly high up, the aquarium may not need to be emptied completely. The site of the leak needs to be dry and accessible.
Scrape off the existing sealant around the site of the leak, removing about an inch in either direction from the leak. Clean the area well with acetone and let it dry.
Use only a sealant intended for aquarium use. Other sealants may contain toxic materials that can leach into the water. Apply the sealant to the area, making sure it gets into the seam between the two plates of glass. Let it cure for 24 hours. Refill the tank, and check to be sure the leak has been fixed.