Question I resealed my tank (42g hex)that I used for fresh water, now I want to do saltwater I let the sealant cure for a week before filling with water and had no leaks its been about 4days filled now, with no leaks and I noticed this on one of the seams on the outside should be concerned? Here is a pic of the seam its started to separate on the outside not sure if it was like this in the past I'm just now notice it and also a pic of the other seam which are closed and fine