It seems to have a slight l leak.
Read and learn http://www.marinetex.com/Marine-Tex_how_to.html#Anchor-How-63368
This is the link to which Marine tex product is correct for the job....... then make you decision from there. In the past I have used gluvit for leaks on my personal aluminum boats.
Pay particular attention to fix leaks in aluminum hulls
I'm not going to get into a debate over which works, they both do, one's cheap the other's expensive, glad it worked for you. If you'd like I can post pics of my son's aluminum skiff and the repair we made two years ago with marine tex and how it's still holding or the fuel tank in my jeep that hasn't leaked at all in five years.