Did you say the retainer ring is also seperating???? If so,THIS IS YOUR PROBLEM...The ring is supposed to be ONE PIECE,so the glass can NOT come apart..You should adresse this problem first.You see,this rim holds the glass together.Then the silicone holds the water in...Then look into resealing the entire seam.....Just use an AQUARIUM silicone for the seam.But all the old sealent will have to be removed first...Then clamp it till it is set.Then you will need to repair that upper rim before you refill the tank...This is what was the main problem with my tank(the rim was broken at the corner)So the weight of the water just kept splitting the seam.I tried to fix it two or three times before I just gave up,and replaced the whole tank...